Man and Science

Citation preview

MAN AND

W.

SCIENCE

HEITLER,

F.R.S.

Professor of Theoretical Physics The University, Zürich

Translated by ROBERT

SCHLAPP

OLIVER AND BOYD EDINBURGH AND LONDON

MAN

AND

SCIENCE

OLIVER AND BOYD Tweeddale Court Edinburgh ı 39A Welbeck London

LTD

Street W

ı

A translation of Der Mensch und die Naturwissenschaftliche Erkenntnis by Profesor W. Heitler. This English edition is published by agreement with Friedr. Vieweg and Sohn, Braunschweig.

FIRST PUBLISHED 1963 ENGLISH EDITION First Published 1963

© PRINTED

IN

1963, W.

Heitler

GREAT BRITAIN BY ROBERT THE UNIVERSITY PRESS,

MACLEHOSE GLASGOW

AND

CO.

LTD

Preface HIS little book grew out of a public lecture I gave at the University of Zürich in the winter of 1960. The original lecture was published in the quarterly journal of the Zürich Society for Scientific Research in 1960. The main ideas on which the book is based date back a number of years. The reason why I have now made up my mind to publish a considered and connected account will be clear from the Introduction. As an active participant in the scientific developments of our time I feel that it is now my duty to give expression to these thoughts. In so doing I make no claim that everything put forward here is new and has not already been said by others. Probably only a small fraction of the relevant literature (which would have to include the pronouncements of philosophers, theologians and scientists in practically all fields) has come under my notice.

Occasional quotations show where I have, more or

less by chance, found parallels to the ideas of this book. My thanks are due to the following, who have helped me by reading the manuscript and providing critical comments upon it. Professor B. L. van der Waerden (Zürich), Dr. P. Rosbaud (London), Dr. H. Heitler (Bristol) and the Rev. H. U. Jäger (Zürich). Much of their commentary has left its trace in the text. I am also indebted to Professor van der Waerden for some detailed discussions of many of the questions treated here. Finally I should like to express thanks of a more anonymous kind. When the main part of the manuscript was complete I was privileged to spend some time in India, a

land into which western science and technology are pouring like a deluge over the soil of an ancient and elevated spiritual Vv

v1

PREFACE

culture. Again and again, and wherever I went, the anxious question was put to me, in one form or another, “how can

we prevent this materialistic science, which we too need so

sorcly, from at the same time destroying our spiritual life?” The only reply I could give consisted, more or less, of

portions of this book. Many talks with Indians, mostly young, including scientists as well as non-scientists, have

greatly increased my

confidence in what

I have said, and

have strengthened my conviction that it is time this book was written, and written by a scientist. To all these young Indians I here offer my sincerest thanks.

THE

UNIVERSITY

ZURICH

Summer 1961

Translator s Preface This translation embodies the alterations and additions made by the author for the second edition published

by F. Vieweg and Sohn, 1962.

R.S.

Contents Introduction

...

ννν “

. Newton versus Kepler

6

. Goethe versus Newton

17

. The Atom

31

. The Science of Living Things . The Cosmos Conclusion

...

54 76 94

To the sage, aware and uncorrupted, came Science, and said to him, “Promise me and swear a holy oath that you will not deliver me up to evil persons, but will impart me only to such as are of open mind and pure in heart. For thus only am I strong and able to feed and clothe mankind. Otherwise I shall destroy you, your disciples and all men.”

Saying (1938) of Swami Dev Maharaj, (quoted from the book Tagebücher aus Asien, by H. H.

von Veltheim-Ostrau).

Introduction T a time when

science

is affecting

our

lives

at an

ever-increasing pace and ever more profoundly, both directly and indirectly through its applications, there

can scarcely be a more topical theme than the relation of science toman. We ought perhaps to say of man to science. But are we really still the overlords, exercising power over our own creation? We read daily that the evolution cannot be reversed. What this means is that we are not prepared to forgo some of the seductive amenities, the wealth, the

power, the lavishly dispensed entertainment, the intoxication of speed and much else that science has given us.

We

would rather put up with all sorts of things that are not beneficial to us as human beings. It is scarcely necessary to mention the well-known evils of mechanisation, of noise

and so on.

Urged on by fear that at their enormous rate of

consumption our sources of energy will soon be exhausted

we are beginning to build nuclear power stations, although as yet no one knows how to dispose of the radioactive waste products which could, if not kept in absolute security,

kill off all forms of life over large regions or contaminate

the oceans.

So far these power stations are few and small.

The problem will arise when they are larger and more numerous. But it seems that we are prepared to incur a

small risk of a great catastrophe. At all events nuclear power stations demand extraordinary protective measures.

Mechanisation has turned industry into a vast machine, in

whose service innumerable human parts of the machine—at least as cerned. Science, from physics to us with undreamt-of advertising I

beings themselves become far as their work is conpsychology, has provided techniques, some of them

2

MAN

AND

SCIENCE

of great subtlety. Probably one of the most disreputable of our inventions is subliminal suggestion in which people arc influenced by flashes of light of short duration which cannot be detected by the eye but produce an eflect subconsciously. If this method should come into common use, there would no longer be any question of freedom.

Here again protective measures are needed—in this case by legal enactments. Examples could be multiplied indefinitely. These are all things that are certainly not conducive to the freedom of humanity. Finally science has opened up the grotesque possibility of destroying out of hand all life on this earth, by nuclear explosions or by bacteria— yet we cannot create a single living cell. One can imagine no greater crime than the destruction of all life on the earth. It is science that first created the means for doing this. Already we often speak of the demonic nature of technology. In view of the facts we have mentioned, and many we have

not mentioned, we cannot help regarding this expression as

only too well justified. In enumerating some of the debit items of the scientific age we must of course not forget the great material blessings this same science has given us—the higher standard of living

in what used to be the famine lands, the elimination of

pestilences and generally the conquest of innumerable diseases by medical science. The fact remains however that many of the applications of our science, more particularly in recent times, are directly inimical to life, even if they provide us with material amenities. We must ask how this comes about. Why is it that having made an invention we have so often immediately to invent something else to protect us from it? Science is based on the desire for knowledge

of nature;

no great discovery ever had any

other motive. How then does it happen that the wonderful profound and beautiful insights we have won, the revelation

of the secret laws of nature, in which we live and to which

INTRODUCTION

3

we belong, often lead to consequences dangerous to our-

selves?

And the dangers are not by any means small.

It seems to the author that it is not only because mankind,

whether from lack of a sense of responsibility or the desire for wealth and power has made and is making these mis-

applications.t

It is so much easier to damage and destroy

life by the aid of science than to create life that—so it would appear—something

of this tendency

must

be inherent

in

present-day science itself. Technology is the offspring of science alone. So we ought properly to speak not only of the demonic nature of technology,

but of science as well.

and indeed directly inimical to life.

Perhaps he will regard

In what does this demonic nature consist? The author does not claim to give a final answer to this question. But the reader will find sufficient evidence in the sequel that modern science itself exhibits traits alien the answer we shall try to give at the end as inadequate, but

the question is there, and we can hardly afford to ignore it. Hand in hand with the advance of science there is an

enormous extension of the scientific way of thought. Since the time the author began to concern himself with physics

the number of persons engaged in research in this field has increased at least tenfold, and an even greater number of people are associated in some way with scientific activity. Creative ideas are of course rare, now as always.

sequence science has to a large extent become

In con-

a manual

trade for many people (there already exists an “Association of Scientific Workers’). What is more important is that

scientific thinking and scientific method are forcing their

way into almost all fields of life.

Statistical methods are

used in business and in civics; and rumour has it that in the

defence ministries of the great powers the outcome of

possible wars

is being

predicted

by “electronic brains”.

1So much has been written about the responsibility of applied science that it is superfluous to discuss it.

4

MAN

AND

SCIENCE

Psychology is widely used in sociology, and has found one of its many applications in the “industrial psychologists” of factories; and there already exists a “science of salesmanship” and so forth. It seems as if science was already trying to assume power over many fields of our activity and to mould man in its own image.

The end-product would be,

judging from the way in which science is widely understood and carried on nowadays, the robot, working eflıciently, well fed by chemistry, brought into the desired state, whether of sleep, of boundless courage or unquestion-

ing obedience, by means of pills, and kept in good spirits by automation of his leisure employments.

Of course the extension of scientific modes of thought

to other fields has many

aspects of positive value.

The

dividing line is not always obvious at first sight. It is useful and necessary to regard, e.g., the industrial

output of a country from the point of view of statistics in order to understand along what lines further development

may best be promoted.

But when some scientist sets up

statistics of all the wars that have broken out in the world in

the course of time, and finds that they have occurred according to the “law of chance’, this involves a hidden

danger.

For it ignores the main point, namely that there

has been a definite motive for each particular war, based on

the psychology of one individual or of many.

It is too

facile to conclude that “the law of chance must hold” like a law of nature, and that therefore the next war

“must”

break out in so and so many years. This would be a typically unwarranted extrapolation from physics. In

physics there are instances where the law of chance holds

and is securely based.1 In the question of the outbreak of 1 The motion of a single molecule in a gas is to a large extent random. The motion is governed by numerous irregularly distributed actions, namely, the collisions with other molecules, from which the law of chance follows. But these collisions are a complete description of the actions on the molecule in question so that the application of the law of chance is justified.

INTRODUCTION

5

war there is no basis whatever for statistics, in which the real cause, depending in every case on free-will decisions,

is passed over. This is only one example out of many.

Much

that could be mentioned in this connection is mere pseudoscience or scientific trash. The regard in which science is held has become so great that anyone with any pretensions at all immediately thinks he must don the scientist’s mantle. But almost invariably it is a case of methods and of modes of thought originally derived from the exact sciences and

then

transferred

to

such as human relations.

something

completely

different,

The reader will be able to gather

from the detailed discussions which follow what the im-

portance of this is. We see that science and its modes of thought have developed an immense urge to expand over all fields of life, including the whole of human thought, and

it is scarcely an exaggeration to say that this tendency is the

most powerful influence to which our era is subject. If we are to understand all this we must understand the

scientific way of thinking. The following sections are devoted to a critical analysis of scientific methods. Although

it was

the

contemporary

situation

outlined

above

that

supplied the external stimulus for the present publication, the investigation which follows serves, completely and indeed primarily, a purpose of its own. We shall investigate what presuppositions are made in the process of scientific discovery, in what relation these discoveries then stand to

man, and what consequences follow for our picture of the universe. In doing so we shall always adopt a point of view from within science. We shall have no further occasion to speak of applications, unless incidentally.

Chapter 1

Newton versus Kepler N writing the history of physics it is usual to start by

mentioning a few great names such as Kepler, Galileo and others, culminating finally in Isaac Newton, the chief founder of physics—as though a straight line of development led from Kepler to Newton. It is of course

true to say that our science began about the turn of the sixteenth-seventeenth century, if we disregard isolated pre-

cursors in antiquity whose tradition was interrupted. It is also true that Kepler’s three laws! were one of the foundation stones on which

Newton

built.

Galileo, a contemporary

of Kepler, is as regards attitude of mind Newton's immedi-

ate predecessor, but he has practically nothing in common with Kepler. When we compare Kepler's great work? (his last) with Newton’s,® a great gulf is evident between completely different intellectual orientations. Almost the only modern feature in Kepler is that he used Tycho

Brahe’s accurate observational material and insisted that a

correct conception of the planetary system must be consistent with it. (In earlicr times this had not been regarded as of much importance.) In other ways however Kepler was still the complete mediaeval mystic; he was above all part Platonist, part Pythagorean. For instance we find in his writings detailed astrological considerations, such as how the aspects of the planets influence the “earth soul”. The 1 They are (1) the planets move in ellipses with the sun in one focus. The line joining sun and planet describes equal areas in equal times. The squares of the periodic times are as the cubes of the major axes. 2 Johannes Kepler, Harmonices mundi, 1619. 3 Isaac Newton, Principia, 1687.

6

(2) (3)

NEWTON

VERSUS

KEPLER

7

validity of astrology was for him a fact,! notwithstanding his

vigorous

denunciation—doubtless

astrological quacks of his day.

justified—of

the

His first attempt to under-

stand the planetary system consisted in establishing a connection between the six planetary orbits and the five regular Platonic solids.” After prolonged efforts he had perforce to abandon the attempt, in view of the observational material.

His next aim was to discover the Pythagorean harmony of

the spheres in the planetary system. tenaciously for many

This aim he pursued

years—until he succeeded.

Pytha-

goras had made the important discovery that musical con-

cords are associated with simple whole-number relationships, for instance the lengths of sounding strings. We now know that it is in general a question of the ratios of frequencies of oscillation. The Pythagoreans also had a notion—call it a theory or an intuition—that the motion of

the planets is accompanied by musical sounds harmonically related, so that the heavens resound with harmonies.

exact origin of this idea is unknown.

The

It is reported of

Pythagoras himself that he was able to apprehend these

harmonies by extrasensory means. However this may be, the next step, already implicit in the Pythagorean intuition,

was obviously to assign whole-number relationships to the

planetary orbits;

to reveal these relationships in detail was

Kepler’s aim. Of the existence of these harmonies he was absolutely convinced. God the Creator, so his argument ran, could have created the heavens only as a perfect structure, even although the earth, for well-known reasons, is no such thing. But harmony was completion. So Kepler 1 He asserts for instance that he has established the influence of the aspects on the weather. 2 As Plato showed, there are only five regular solids, 1.6. symmetrical bodies bounded by identical equilateral polygons, while in the plane there are arbitrarily many kinds of equilateral polygons. The five regular solids are:

tetrahedron,

cube,

octohedron,

dodecahedron,

icosahedron.

They

are bounded respectively by 4 triangles, 6 squares, 8 triangles, 12 pentagons, 20 triangles, all equilateral in each case.

8

MAN

AND

SCIENCE

divines the Creator’s aim, and this aim was so to create the

planetary system in order that the harmonies might resound in heaven, for ears that can hear them.

So the question was where in the planetary orbits these whole-number relationships were to be found. Was it for instance in the distances from the sun, or in some other

feature? To this single purpose his laborious year-long study of planetary motion was devoted. In the course of it Kepler also discovered—as a by-product—his three laws, 1.6.

the elliptical form of the orbits and so on.

was, however,

an intermediate step.

He

For him this

never

set much

store by this discovery, for which he is famed today.

In

the end, when he was nearly fifty years old, he found what he was looking for. He found that the angular velocities of

each individual planet at perihelion and aphelion are, to a

close approximation, in the ratio of simple integers, and

thus correspond to a musical interval. The system of the six planets gives the whole major or minor scale, depending

on whether one starts with the perihelion or aphelion of Saturn. This was Kepler’s triumph; his life-work was

completed. Let us try to analyse the course of Kepler’s thought. It is clear that his guiding principle is markedly metaphysical and theological. But this is not its most surprising feature. Whether he is aware of it or not, the modern theoretical

physicist also allows himself to be guided by at least one

metaphysical principle. In his search for new laws of nature he uses the idea that they must be capable of formu-

lation in a mathematically simple and perspicuous manner. Without

this guiding principle scarcely a single general

physical law could ever have been discovered. No law is discovered from experience alone, although empirical material plays an important part. In the first place there is

no such thing as exact agreement

between

the law and

experience, because there are always disturbances, such as

NEWTON

VERSUS

KEPLER

9

friction etc. and secondly there are no exact facts of experience, for every measurement is inexact. But why

should physical nature be mathematically simple?

is no logical reason;

There

it is a metaphysical conviction, and we

could amplify it by saying that we are convinced that the

Creator can have made the laws of nature only in simple

and mathematically

elegant form.

But unlike Kepler we

no longer openly maintain this (or something like it), though Newton and some of his successors still said it

explicitly.

At all events the physicist has made successful

use of this guiding idea.

The fundamental distinction between Kepler and later science lies in the structure of the laws for which he is

looking.

The Keplerian type of law has to do with the

planetary orbit asa whole. in

combination,

and

these

Motion and orbit are considered orbits,

arranged on harmonic principles. in order that the harmony

of the

as

Kepler

found,

are

They are such as they are spheres

may

resound (for the adornment of the world, he says).

exist and

Thus we

have to do with teleological arguments, i.e., with purposive

considerations that concern the world as a whole.

The

world is what it is in order that something else may be so, and

not because it is necessarily so or because there is a reason for

it.

Kepler’s research is directed to finding the purpose and

understanding it.

We shall frequently come back to tele-

ological considerations.

Quite a different course was taken by science in the

hands of Galileo and Newton, and ina tremendous crescendo

since their time.

Newton is the true discoverer of laws that

are differential, causal and deterministic.

Consider

New-

ton’s fundamental second law—a body moves in such a way that at each instant its acceleration (i.e. change of velocity in unit time) is equal to the force acting on it, divided by its

mass. The motion is thus determined only from one instant to the next. So the law is differential. For every change in B

IO

MAN

AND

SCIENCE

speed there is a compelling cause, force.

causal.

So the law 1s

The whole motion of the body in its path is obtained

by integrating all these instantancous actions.

The orbit can

be worked out in advance with complete precision if (1) the force is known, and (2) the position and velocity of the body have prescribed valucs at a certain initial instant. We call these the initial conditions.

pletely predetermined.

In this case the future is com-

So the law is deterministic.

It is in

this deterministic property that the immense power of the

law resides.

No wonder that the whole of later physics—

up to 1925—followed the pattern of causal deterministic laws.

Let us now compare Newton’s law and its consequences

with Kepler s type of law. mathematical consequence

In the first place it follows as a from Newton's law, together

with the law of gravitation (also due to Newton) that the

planets

move

in ellipses,

with

the further

properties

ex-

pressed by Kepler's three laws. The latter are thus a consequence of the Newtonian laws. The actual planetary

orbits however do not by any means follow.

What does

follow is merely a series of possible orbits, small, large, nearly circular or elongated ellipses. The actual orbits of our planets are a particular selection from among these possibilities. The harmonic relations of Kepler are therefore not a consequence of Newtonian mechanics. For this reason Kepler’s three laws have become a part of present-day science, while the harmonic relations have been eliminated. The former can be derived from causal mechanics, but not

the latter.

It will not do to argue that the harmonic rela-

tions are not exactly fulfilled.

fulfilled in nature.

The

No physical law is exactly

planetary orbit is not exactly an

ellipse because there are always small perturbations, e.g. by a third body, such as another planet.

To fix the actual plane-

tary orbits according to Newton it is necessary to know the

initial conditions.

To determine them in the sense of a

NEWTON

VERSUS

KEPLER

II

causal science we would have to go back to the origin of the planetary system some thousands of millions of years in the past (cf. Chapter 5). At present we know nothing definite about this. At all events the initial conditions seem to be determined more by chance than by any obvious regularity. So the actual planetary orbits become a chance selection from among all possible orbits.

Thus Kepler’s aim was considerably more far-reaching. He wanted to fix the actual orbit by his teleology. Had he known the Newtonian laws he could quite readily have accepted them (and probably would have done so with his characteristic enthusiasm): but they would not have solved his particular problem. He could still have discovered and upheld his harmonic relations. He only needed to say that what appears to Newton as chance is the purposeful work of the Creator. Whether we speak of “the origin of the universe which, as we shall see in Chapter 5, is probably

beyond the range of scientific treatment, or of an “act of creation’ depends largely on our metaphysical attitude. At first sight causality and teleology appear to be completely opposed to each other. The mental attitudes involved in setting up and considering the two types of law are wholly distinct. Perhaps this is the reason why Galileo took scarcely any notice of Kepler. Nevertheless it is important to bear in mind that the two ways of looking at the matter are not necessarily contradictory. In many cases they are mutually complementary. In physics there are indeed cases where a causal law is identical with a teleological one. If a ray of light passes through a medium of variable refractive index, its path is no longer a straight line. A ray of light traverses the atmosphere in a slightly curved path (as a result of which the setting sun appears slightly oval in shape). There is a causal law for the path of the ray, similar to the

Newtonian law of motion.

path by a teleological law:

But we can also determine the

the ray of light travels by such a

I2

MAN

AND

SCIENCE

path that the time it takes between two fixed points 15 a minimum. The two laws are mathematically equivalent.

Again a machine naturally obeys strictly causal laws: but we

can understand it properly only if we know and have in-

vestigated the purpose of its constructor. ology supplements the causal law.

In this case tele-

Again, in our example of the planetary system causality

and teleology could be mutually complementary. The causal laws provide a broad framework (the possible ellipses)

leaving room for the chance initial conditions necessary to determine the actual orbits.

A priori it is quite conceivable

that for a complete understanding of the planetary system

this vacant place might have to be filled by teleological laws of Kepler’s type, which actually fix the planetary orbits.

Here a teleological law would supplement a causal law, by substituting a kind of over-all plan for the unknown

and

chance initial conditions. It is to be understood that nothing is thereby said about the real truth-content of Kepler’s harmonic relations, either for or against. Our considerations were intended solely to clarify the relation between causality and teleology. But we shall see in Chapter 4 that we have every reason to considerations into other Here and throughout in the narrow sense of the

admit or to introduce teleological fields of natural science. the sequel the word causal is used exact sciences. From the data at an

instant of time the course of events immediately afterwards follows of necessity.

Thus causal does not mean simply that

there is a reason or a motive (in this latter sense an action with an aim in view would be causal;

motive.

the aim would be the

But that is not the sense in which causality is

meant here). Causal and teleological are fundamentally different attributes, although it may happen that both are necessary for the understanding of any particular phenomenon, as we have seen.

From Newton's time on the causal idea takes over the

NEWTON

VERSUS

KEPLER

13

whole of science, gradually at first, and then at a breath-

taking pace. Science moves towards an unparalleled blossoming—and mankind at the same time towards the danger of a catastrophe, in more senses than one.

First the exact

sciences celebrate their triumph. Almost all the achievements of physics, chemistry and astronomy up to 1925 and to

a great extent till later follow the pattern of Newtonian

causal and deterministic laws. It is not necessary to elaborate this. Physics itself was compelled, from 1925 on, to depart

from this strict pattern—but more of this later. The

causal idea then encroaches

on other sciences, on

biology and psychology and, from the nineteenth century onwards,

even on other fields of learning.

This may

be

illustrated by a few examples. Primitive views of nature have always made use of teleological arguments. The frog is green in order that it may not be scen in the grass by its enemies. The reader can find hundreds of other examples. The genius of Darwin converted this explanation into a causal one. The frog is green because red, yellow and blue

frogs have long since been devoured by their enemies, or would be devoured, so that only frogs that “happen” to

have the appropriate protective coloration have been able to survive. Karl Marx introduces the causal argument into his view of history. The course of history is the consequence of the interplay of mutually opposing economic forces. He or his successors go so far as to conclude that history follows an inexorable and deterministic course, just like mechanical

motions in physics. Examples could be multiplied at will. Not everything of this sort, however, merits the name of

science.

It has almost come to this, that anything that is not

causal (and quantitative, see Chapter 2) is unfit for polite

scientific society. The reasons for this growing trend towards the causal are at least in part easily recognisable. It is above all the

unparalled success of the exact sciences that has carried

I4

MAN

conviction.

AND

SCIENCE

For there is nothing so persuasive as success.

This

began the process of “re-educating” the thought of scienti-

fically thinking persons in the new direction. Secondly a metaphysical reason undoubtedly plays an important part.

Let us again consider telcology, as a counter-example to the idea of causality. A teleological argument pre-supposcs, outside the object of scientific study, some being endowed

with intelligence which has determined the purpose.

The

question of such a being is too obvious to be simply evaded.

In the age of rationalism (which science itself brought in its train) such a question was inappropriate.

In investigating

causal laws we could rather be content simply to discover the laws without bringing up the question of the origin and meaning of these laws. This does not of course dispose of

the question, but it can be ignored (and is ignored by science) or relegated to philosophy. We shall have occasion to speak of this point in greater detail later.

The irruption of the causal order of ideas into almost all

fields of life is a first step leading away from what is human, and the division between science and man begins. (In the

next Chapter we shall learn what the second step was.)

As

human beings we do not in general think and act causally

(in the sense explained above).

We act with aims before us,

if only the modest aims of daily life.

We feel ourselves free

to act in this way or that, even when we are subject to certain

psychological or other influences, and are conscious of these.

At this point there is a sharp contrast between causal deter-

ministic thinking and human life itself.

Any transfer of the

deterministic principle to human affairs, including psychology, sociology, history and so on is bound to lead to most

serious consequences for humanity. If we really follow the the principle of determinism to its logical conclusion and apply it to everything, including man and his psychic and

intellectual life, and to human society, the result would be that life would become a huge inescapable and meaningless

NEWTON

VERSUS

KEPLER

15

machine, in which there is no place for the word freedom. For determinism and freedom are simply not compatible. We would also have to expunge from our dictionarics the word ethics and everything associated with it. A machine has no morals. The penal code would no longer make sense, for we cannot punish a machine for running according

to natural laws. We sce that this process leads to a complete demoralisation of which presumably scientists themselves would be the first victims. The entire social organism would collapse,

and

the final state would

probably

not be very

different from Orwell’s “1984. The symptoms mentioned in the introduction and many others that have not been mentioned show that humanity

has already taken a first greater or lesser step in this direction.

The unthinking transference of deterministic thought to matters in which it has no place must be regarded as one of

the most dangerous tendencies of our time, the more dangerous as it takes place only half-consciously and under the guise of "science.

Determinism has its place in exact science, particularly in physics, and even there its place is a limited one. Physics itself, in its most recent phase, has now abandoned this

principle in its strict form. of atoms,

This phase concerns the world

the so-called quantum

mechanics,

discuss it in more detail in Chapter 3.

and we shall

But even in classical

(i.e. pre-quantum) physics the meaning of determinism is

theoretical rather than practical. As Born! has recently emphasised, the exact prediction of any process requires exact knowledge of the initial conditions. Such knowledge

is however impossible owing to the essential inaccuracy of all measurements. Moreover, even if the initial conditions

are known, prediction is possible only for simple processes.

Very complex processes are not amenable to mathematical treatment, even with the aid of electronic computers, Pre1 Max Born, Physik und Politik, 1960.

16

MAN

AND

SCIENCE

diction is then, in the nature of things, impossible.

For

instance, the motion of a single drop of water in a waterfall is something that is impossible to predict even if we know

accurately the flow at the top rocks. In practice determinism of the course of a laboratory constructed machine, up to the of certain inaccuracies,

the machinery.

some

and the distribution of the is confined to the prediction experiment or of a wellpoint where, just on account

unpredictable fault occurs in

Good conditions for prediction are realised

in astronomy and perhaps in a few other instances, but certainly not for most of the familiar terrestrial natural phenomena.

In all human concerns, the causal and deterministic mode of thought has no place—or at most a very modest one. There may be a gradation of intermediate stages in which the principle of causality has limited validity;

presumably this

applies in biology (cf. Chapter 4). What we can assert here

is that a general world-philosophy based on the principle of

determinism is entirely without foundation.

tion to human

affairs not only cometh

completely unwarranted.

Any applica-

of evil, but is also

Chapter

2

Goethe versus Newton ESIDES its causal aspect, modern science possesses another essential characteristic, that of being quantitative. Inall exact sciences, 1.6. those that deal with the

inanimate world, the word measurement is written large.

Moreover, the measurable, that is the quantitatively observable, is the only thing that is admitted, used and turned to

account scientifically as a phenomenon of the external world. It stands to reason that in the pursuit of science we have to rely on our sense-impressions.

But these are predominantly

of a qualitative kind. The only thing we can perceive directly and follow quantitatively by simple means such as graduated scales and clocks is the motion of a body. On the other hand colours, tones, odours and so on are purely qualitative, and there is no way of apprehending them quantitatively. We cannot measure the colour “green, the

scent of a rose or the like.

How does physics treat these

phenomena? Asan example let us consider light and colour. Colour itself is something that has not entered into physics

any more than Kepler’s harmonic ratios, although colour is

the dominant feature of our sensation of light. But physics had no use for such qualitative sensations. It took some

time before it was found possible to isolate a quantitatively measurable element from thc phenomena of light, by

means of suitably constructed apparatus (such as the spectro-

scope etc.).

Indeed it was not until the time of Maxwell,

Hertz and others towards the end of the nineteenth century that physical optics achieved finality. The time-lag as compared with Newtonian mechanics is easy to understand, 17

18

MAN

AND

SCIENCE

As we have said, the quantitative side of the motion of bodies can be recognised very casily by the simplest means.

The

quantitative

side of optical phenomena

is essentially

more recondite, and our sensations give us no direct evidence

of it.

In order to recognise it, it was first necessary to dis-

cover the quantitative substratum, the “vehicle” of light.

This is, according

to the teaching

of physics, the electro-

magnetic field, and it is electromagnetic waves that constitute

light. These are in themselves invisible; their existence can be recognised only by experiments of various kinds with

suitable apparatus and by more or less indirect theoretical

inferences, that is, inferences involving thought-processes.

But these waves are the only feature that can be measured

quantitatively. Instead of colour the wave-length, which can be given in centimetres, now comes in. To a definite

wave-length a definite colour can be uniquely assigned. (In the reverse sense the assignment is not quite unique.) The

sole object of physical investigation is now no longer the

colours, but only the waves.

The electromagnetic waves

themselves obey laws just as causal and deterministic as those of mechanics.

We treat a phenomenon scientifically only after we

have succeeded in discovering a substratum associated with the phenomenon and describable in quantitative terms;

light the substratum

sound the elastic waves

is the electromagnetic waves,

of the air or of other bodies,

for

for for

odours the chemistry of the molecules concerned and their

reactions, and so on.

Science demands

quantitative state-

ments, rejecting from the outset anything that is qualitative.

(For the moment we are speaking only of exact sciences.)

Science goes a step further in claiming that the aforesaid quantitative substratum is the only thing that can appro-

priately and with any justification be called the objective external world.

Our immediate qualitative sensations are

relegated to the domains of physiology and psychology.

GOETHE

VERSUS

NEWTON

Consider colour once more as an example.

IQ

The external

reality is the electromagnetic wave;

it gives rise, in the eye,

to certain physiological processes.

But then comes the

then in the optic nerve, then in the corresponding brain cell,

mystery—the

point

at which

all these

material

processes

suddenly turn into the colour sensation “green”.

On this

(we count the electromagnetic ficld in this sense as material)

point all the sciences concerned, namely physics, physiology, and psychology are completely in the dark, because

there is no bridge between physiology and psychology, that is, between material and psychical processes. Thus we see that the exact sciences lay down two definite

principles at the outset.

(1) Only quantitative phenomena

come within their scope, the qualitative being the concern

of psychology, and (2) these quantitative phenomena alone

belong to the external world. It seems that Galileo was the first to express this philo-

sophy clearly.

It is significant that the very man who so to

speak wrote the introduction, in an intellectual sense, to Newton 5 mechanics should also have created the conceptual

basis for later science, although at this time and for long

afterwards there was no question of an understanding of the phenomena of light. Thus our two principles are just as old and no older than our science itself. We must now ask what is the justification for formu-

lating these principles.

Are they necessary, and are they the

only possible ones, or could we proceed in a different way? If so, we must be clear as to the consequences.

In the first place we can adduce the success of the principles in their favour. It is doubtful whether there is really any other justification. It was by this route that a connected

logically closed mathematically expressible picture of the external world was arrived at (we must not speak of it as an all-inclusive or global picture (“Weltbild”) since we shall

20

MAN

AND

sce that it is no such thing).

SCIENCE

It is a picture that embraces

innumerable phenomena, a picture of seductive beauty and

profundity, at least for anyone who finds beauty in logical

clarity and mathematical elegance; a picture of the world detached from all human elements, that of itself obeys

strictly deterministic and quantitative laws of the type of Newtonian mechanics. For the world of atoms the description deterministic is not as a matter of fact quite appro-

priate (sce Chapter 3).

Of the success of this picture as

regards applications there is no need to speak further.

But all this does not answer the question whether our

principles are necessary.

It can hardly be denied that they

involve a certain degree of arbitrariness. Natually we are free to sclect certain classes of phenomena for the purpose of scientific treatment and to reject others. But we must be

clear that we then inevitably obtain an incomplete picture lacking general validity. The primary question is what we

declare to be the objective external world. We have expelled colour from the objective world and relegated it to our inner life because it is non-quantitative. But unprejudiced consideration will confirm that in general we feel entirely as if colour belonged to the external world (if we have not already been infected by science). We say “grass

is green” and not “we perceive grass as green’. It is not at first obvious why “being green” should not be an objective

condition belonging to the external world just as much as the wave that represents green light. “Green”, as something objectively apprehended, is on precisely the same footing as

any quantitative observation, and we might with equal

1 There is to be sure an essential difference between the perception of a colour and a quantitative observation, in that the colour is directly given while a quantitative observation presupposes the operation of thought in some measure. This does not alter the situation that both are objective perceptions and there is no reason why the one should be more objective than the other. One could indeed take the view that anything as directly given as colour is more objective than something that presupposes a lengthy mental process.

GOETHE

VERSUS

NEWTON

justification ascribe the reading

21

of the result of every

measurement to our inner life. Above all it is not clear what the quantitative and the external world are supposed to have to do with each other. We have evidently arrived at the central problem posed by our theme: where does the frontier lie between the external world and our inner life as human beings?—the old philosophical question, to which there are innumerable

answers,

none

of them

conclusive.

At the opposite pole we have the thesis of Buddhist philosophers that the phenomena of sense aré mere appearance, or, somewhat differently expressed, that there is no such

thing as the external world, and that all phenomena, including the quantitative, are only human experiences.

even possible to refute this thesis.) Naturally

it is necessary

to

draw a

(It is not

line of division

between the external world and our inner life, in order that we may be able, as apprehending subjects, to confront the

external world at all.

The only question is whether this line

is fixed beforehand, or whether a certain amount of arbitrariness remains. We shall see that we have every reason to

adopt the latter point of view.

The situation we have decribed is probably the deeper reason for the violent polemic that Goethe waged against Newton on the doctrine of colour. Goethe adopted a point

of view diverging from that of physics; herein lies the fundamental significance of his doctrine of colour for our enquiry; and we shall therefore consider it in greater detail. Newton

had

already

set up

a crude

theory

of light and

colour. In particular he concluded from the well known experiment with the prism that white light is compounded of all colours. Moreover the Newtonian theory already contains an adumbration of that quantitative substratum, still in primitive and

represent

untenable form, that is supposed to

the vehicle of light, namely the well-known

light corpuscles, of which light is supposed to consist, and

22

MAN

which

were

theory

of light with

waves.

AND

subsequently

SCIENCE

replaced

by

electromagnetic

In short, Newton had hints of the later physical the

same

quantitative

features.

Gocthe vehemently contested this.

see the reason for his aversion.

and

causal

It is not difficult to

His standpoint was roughly

that the physics of light is simply the knowledge

of our

immediate sensations of light (in so far as they are objective and not illusions of the sense—he

latter).

clearly distinguishes the

The sensations of light are what we experience of

light, and are also the only thing on which we can build.

Our sensation of light is, so to speak, the definition of light.

There is no clear-cut boundary

separating off our sense

impression from an invisible hypothetical external world; the external world is identical with objective perception.

Thus human experience is central, (as of course for Goethe man was all-important).

We see “white” as a single, indeed as the simplest, colour and not as something compound. The Newtonian

thesis conflicts with this elementary experience, and is there-

fore bad. Goethe's expression for it is “the loathsome Newtonian white”. For Goethe the conceptual model of light, the light corpuscles, the search, that is, for the quan-

titative substratum,

was

‘disgusting’.

Electromagnetic

waves would scarcely have been more acceptable to him. Our

sensations

of colour

are

qualitative,

and

thus

the

physics of colours is also something predominantly qualitative. This was the cause of his opposition to the “exaggerated application of the art of measurement”. Perhaps there is already latent in this an intuitive premonition of what the consequences of a science would be that makes “unlimited use of the art of measurement”, or if this science should come to be regarded as the only valid kind. It must also be mentioned that Goethe was a great admirer of the art of

measurement in mechanics and in geometrical optics, which

GOETHE

VERSUS

NEWTON

23

deals with the paths of light-rays.! Goethe’s attempt to refute Newton was of course misguided. It probably arose

from the wish to keep science “human” at all costs—the reverse of the modern tendency. Clearly however he did not understand that a purely quantitative science was a

logical and practical possibility. Goethe

then developed

his own

theory of colour in

opposition to Newton, which kept him busy for ten years.

We

shall consider this briefly.

Rejecting

all conceptual

models, this theory attempts to operate only with the idea of colours themselves, and to connect colour phenomena, just

as we observe them, directly with each other. At the apex of any theory the physicist puts a fundamental law (e.g. Newton’s Second Law of motion in mechanics) which can-

not be based on logic alone, but is obtained as a summary of facts of experience, combined with theoretical considera-

tions.

In the same way Goethe has to put something at the

apex, which he calls the “primitive phenomenon”

nomen).

(Urpha-

It is the simplest colour phenomenon, namely the

phenomenon that in the first place allows colours to emerge at all out of white uncompounded light. As his primitive

phenomenon Goethe uses the following two facts. white light passes through a turbid medium

When

it becomes

yellow or red. Further, if we look at the light scattered sideways by the turbid medium against a dark background,

the latter appears blue. Everyone is familiar with this phenomenon from daily experience—the red of the setting sun, the blue of the sky.

of colours.

This then is for Goethe the origin

Of course all this can be derived from the

1 Goethe’s attitude to the physics of light of his day (which was of course considerably in advance of Newton) can be seen from the following verse: Though you break light into fragments / and produce out of it hue upon hue / or play other pranks, / polarise small spheres / so that the startled hearer / feels mind and senses come to a standstill, /no, you shall not succeed, / you shall not deflect us; / vigorously as we began / we will win through to our goal. In point of fact he went wrong in the fourth last line.

24

MAN

AND

SCIENCE

physics of light, in a rather complicated way. The physicist knows that shorter waves (blue light) are scattered more

strongly than long waves (red light). If more short than long waves are scattered from white light which contains all wave-lengths it is predominantly the long waves, i.e. yellow

and red, that remain, and the scattered light is blue. Building

on this primitive

phenomenon,

Goethe

then

develops other colour phenomena and relates them to each

other. His aim was to understand all colour phenomena as consequences of the primitive phenomenon. We need not however, go any further in this direction.) We are con-

cerned not with the factual content, but with the formulation of the problem. Goethe’s doctrine of colours thus operates exclusively

with the qualitative colours. These he regards—since they

are objective phenomena—as undoubtedly belonging to the

external world; any other world (the waves) does not exist

for him.

The physical conception is different.

Colour

phenomena belong partly to the external world (as manifestations of wave processes) but partly to our inner life, as human sensations. As seen from the point of view of physics Goethe’s doctrine of colour is set in the region where the external world of physics and our sensations come together and form a unity. It deals directly with the

phenomena of light and colour.

Of course there is no

question of Goethe’s having actually explored this region in

detail. For this it would be necessary, as judged from our present state of knowledge, really to understand the precise

connection between the colour quality and the quantitative wave,

a goal from which we are inconceivably remote.

(Nothing is of course achieved by merely assigning wavelength to colour.)

What Goethe’s attempt to develop a theory of colour on the lines described suggests to us is, however, that it is quite 1 Goethe’s theory of colour has since been developed much further.

GOETHE

VERSUS

NEWTON

25

possible to take the view that colour belongs to the “objective external world”, so that we can displace the boundary

in this sense, in contrast with the standpoint of modern physics. This can also be made plausible as follows. Physics has sharply delimited the external world with which it deals in accordance with its quantitative point of view. If we also include in this world the physiology of the

process of seeing—e.g. eyes, optic nerve, brain cell, which we also investigate by physico-chemical means, the final point, the transformation into the sensation of light, remains

a complete mystery.

It is at this point therefore at the latest,

if not before, that we meet a fundamental limitation of all

investigations using the methods of present-day science. Nor is it purely a question of psychology, for this can only describe and compare psychic processes among themselves.

As long as we keep to the standpoint of physics it is rather

a question of the interplay of two worlds, a physical external

world and our inner life, (including of course that of animals) an interplay that manifests itself in all sense perception. Since there is clearly such an interaction and the two worlds—external world and inner life—do not exist for themselves alone and are therefore not sharply separated, it

is not to be assumed that a distinct, unambiguous boundary,

free from arbitrariness, exists between them. So we are forced to the conclusion that the boundary can be displaced, that is, to revert to our previous example, that

colour may be counted as also belonging to the external

world, as it would in Goethe’s colour theory. Consequently we must ask whether it is conceivable that the

quality of colour (and of course numerous other qualities)

already exists outside ourselves and that the only reason our

science takes no cognisance of them is that it restricts itself

from the outset to the quantitative aspect. Or must we really suppose that the world around us consists solely of measurable data, and that everything that is qualitative is C

26

MAN

AND

SCIENCE

tied up exclusively with sentient living beings? It would be difficult to give a sound reason for this view, although it is the position adopted by our science. It would for instance be a false conclusion to say “colours do not exist when there is no living being present to see them; hence colours exist only in living beings”. By the same logic we could argue that electromagnetic waves do not exist when there are no beings present who can measure them. One could indeed add that their regularities do not exist if no physicists are present to understand theoretically and to calculate their behaviour.

We can indeed go further and conclude that a displace-

ment of the boundary in the above sense is not only con-

ceivable and possible, but is necessary if we are really to gain

an understanding of the qualities that manifest themselves

in our sense-impressions.

That is, that it will be necessary for

this purpose to treat these qualities as naive consciousness does, as objects of the external world.

As apprehending sub-

jects we can set up relations between different phenomena

of the external world. In science we have succeeded in revealing relations between completely different quantitative phenomena, as for instance between electricity and light

waves.

We can imagine that some day we shall succeed in

understanding relations between quantities and qualities as

well (e.g. between wave and colour), when qualities are treated as objective phenomena. As such both would then be on an equal footing. Wave and colour would appear as different manifestations of one and the same object, while

physics has hitherto included only the one, the quantitative

wave. But we can scarcely imagine how we can ever comprehend the sensation of colour if we adopt the standpoint

of contemporary physics and physiology.

In this case the

ultimate recognisable feature consists of processes in the brain cells, electric currents, chemical transformations and so on. How are we to understand that these processes are then all at once something completely different in our con-

GOETHE

VERSUS

NEWTON

27

sclousness—the colour green? We said “are”, not “become”.

For the description of the process of seeing given by scientific physiology contains nothing beyond these physico-

chemical processes. There is no further step to take, nor can

any further step be taken within physiology.

Physico-

chemical processes in the brain ought therefore to be directly

equivalent to the sensation.

This is an impossibility.

The

present standpoint of physics cannot therefore be upheld

indefinitely if we are not to limit ourselves permanently and renounce the possibility of understanding all qualities. Of course the solution of these problems must be reserved for the future—perhaps the remote future. At the moment it would be extremely difficult to bridge the gap between

present-day quantitative science and the qualities, especially

considering how completely we are all “broken in” to the mental attitude of contemporary research. Yet we have here to do with one of the most important and fundamental

problems of science.

Let us return to our present-day science.

There is one

conclusion that we may safely draw from our reflections,

namely

limited.

that our present scientific methods are in principle

We

have imposed the limitations on ourselves.

Even if we assume that the concepts colour, tone, odour etc. make sense only in relation to a living organism, while the

world around us consists solely of measurable objects, we are confronted, not indeed with a physical problem, but

with a biological one.

At all events it is not possible for

biology to restrict itself purely to the discovery of physicochemical processes in the living body. Thus a causal quantitative science is certainly not a complete picture, and hence

isnot a “picture of the world”. It provides a partial picture, only an aspect of the world, a sort of projection of the world on to a causal-quantitative plane, just as a photograph is a projection of the three-dimensional landscape on to the plane of the paper.

At least one dimension, we might say, is lacking.

28

MAN

AND

SCIENCE

From this causal and quantitative projected image practically every human clement has been consciously eliminated. As human

beings we do not think and feel quantitatively,

any more than we think and fcel causally (in the sense of Chapter 1). And science prides itself on this detachment from every human clement. The word “anthropomorphic” has become a term of abuse in science. Of course it is precisely this consciously non-anthropomorphic attitude that has made the successful investigation of the causal and quantitative side of the world possible and has afforded the most amazing insights. As long as we are aware that we are dealing with a projected image, there would hardly be any real danger. Where the danger lies is in the over-valuing alike of the quantitative and of the causal element. The desire to generalise seems to be a universal human tendency. How often has it happened that a few valid insights or discoveries have become a complete and binding universal philosophy. So it is in the present case. The quantitative aspect infiltrates into regions where it does not belong, and proclaims itself as the only thing that is scientific. The great success of science and its resultant great prestige mis-

lead people to form a scientific “world-picture”. This is the mechanistic-materialistic picture of the world that is now so widespread (although we are not always prepared to admit our adherence to this philosophy). The world, including

living

creatures,

becomes

a senseless

machine,

running

mechanically and quantitatively, which has just to be accepted and which cannot be altered. But this conception means not merely an over-valuation of the quantitative, but at the same time an under-valuation of everything that is not quantitative, including man; a devaluation, in the extreme case, to the absolute zero.

Man, regarded quan-

titatively, consists of very interesting chemical substances,

possessing even more interesting functions and reactions—

but then he is no longer a man.

GOETHE

Thus

physics’.

VERSUS

there is no such thing

NEWTON

29

as a “world-picture

of

Any attempt to make present-day science into a

world-picture necessarily leads to the suppression of man—

or to a sort of split personality, in the popular sense of the term.

Our view of the world is scientific, that is, material-

istic and mechanistic, but our life is the reverse.

We cannot

hold a mechanistic philosophy and at the same time talk of freedom. The reader will have no difficulty in recognising in what

has been said at least one of the root causes of the symptoms

mentioned in the introduction. The limitation to the causal and quantitative aspects has led to an estrangement between science and man. This is also noticeable in the field of modern physics. Adherence

to the causal and quantitative led physics, quite logically,

first to atomic

physics,

then to the investigation of the

ultimate units of matter, the elementary particles.

It is here

that the unsolved problems lie. The reader will be able to gather from the next chapter that we are here concerned with fields of the greatest interest from the point of view of

science and its philosophy.

Nevertheless we can hardly say

that these problems have much to do with nature around us.

We investigate these particles, which can be detected only

under artificially produced conditions and to a large extent

exist only as artificial products,! and for this purpose great

particle accelerators are required, as big as a factory. In general this scarcely concerns man at all, unless he hopes to

make technical use of it (nuclear energy, etc.). In contrast, the real phenomena of nature, which are governed by

qualities, and which are excluded from physics, are to a large extent not understood. This is not of course an argument against this line of investigation in itself. Now that we have seen that causal and quantitative 1In cosmic radiation these “‘artificial’’ particles occur “naturally” in small numbers, but this is quite irrelevant for the phenomena of nature.

30

MAN

AND

SCIENCE

science describes “only” a projected image of the world, the

question naturally arises how this partial image could be extended further into the missing dimensions. Clearly there arc regions which have hardly as yet been explored

scientifically if at all.

It is in these regions that everything

that is non-quantitative must occur, such as the qualities of

colour, tone, odour, etc.; all those things must occur that have reference to the connection between physico-chemical material processes and the inner life of animals and humans—

and much else besides.

We cannot claim that we know any-

thing fundamental about these matters. But before we return to this it will be advisable to consider the most recent phase of physics, in which the question of determinism takes on an essentially new and different complexion.

Chapter 3

The Atom F we were to describe briefly the structure of the exact

sciences (physics, chemistry, astronomy) as it has so far presented itself to us, the picture would be roughly as follows. There exists outside of man and all living beings a

world subject to strict quantitative and deterministic laws. The laws are formulated mathematically; they are more or less of the type of Newton’s second law of motion. Once the initial conditions are given the future follows with

mathematical precision. This world is completely detached from and independent of man and his sense-impressions (not to speak of the rest of his inner life). It follows its prescribed

course whether we are observing it or not. We can observe it with all sorts of measuring instruments, a process in which we must of course ultimately invoke the aid of our sense impressions to read the instruments. This does not however

alter the course of this world in any way;

our observation

does not have the slightest effect on it. Nowadays physical laws are often assumed to hold for living organisms as well. At the beginning of the present century the advance of science had made it possible to begin investigating the atom

and the world of atoms.

It is unnecessary to trace the long

and arduous path that led to the demonstration of the real existence of atoms and the recognition that the atom itself

is a composite

structure,

consisting

of nucleus

and elec-

trons. The story is sufficiently well-known even to nonphysicists. The investigation reached its conclusion in 1925

or soon after,! with the discovery of the laws holding inside

1 We shall not discuss the unsolved problems of relativistic quantum mechanics and allied fields. 31

32

MAN

AND

SCIENCE

the atom, that is of the mechanics obeyed by the atomic

particles.

We call this mechanics the mechanics of the atom

or quantum mechanics. It turned out that description of physics required drastic revision.

the above Individual

atomic systems obcy laws which are not strictly determin-

istic.

Morcover there can no longer be any question of com-

plete detachment from the human observer as soon as he carries out observations on single objects. Here the important word is “single”. If we have to do with a large number

of atoms, e.g. in a body even as small as a dust particle, they obey, when regarded as a whole, laws of the same kind as

those of pre-quantum physics.

There can of course be no question here of a complete

exposition of quantum-mechanical laws, let alone of deduc-

tion or discussion of foundations.

We

content ourselves

by simply stating a number of facts which will give us enough insight, and then drawing the conclusions.

We imagine a large number of identical but separate atoms on which we perform certain observations or

measurements;

we

shall

make

these

partly

on a

single

selected atom, and partly also on the whole series of atoms in succession. The simplest atom, that of hydrogen, consists of a nucleus and only one electron. The electron will then

be in the vicinity of the nucleus and will be moving in some way. Weare interested in the position and motion, that is in the orbit of the electron. The reader must take the

author's word for it that it is in principle possible to measure

the position of an electron at a given instant, that is, to

determine accurately the point of space at which the electron

is situated.’ There is nothing to prevent us from repeating this measurement of position on the same atom at equal 1 Although such a measurement is particularly difficult in the case of the hydrogen atom, there are numerous cases in which we can actually measure the position of an electron. The conclusions we shall arrive at below from our ideal experiments could equally well be drawn on the basis of real experiments.

THE

ATOM

33

short intervals of time; in this way we would obtain an orbit—and we would certainly expect a nice curve of some kind, for instance an ellipse, like the orbit ofa planet. Many pictures of this sort have appeared in popular magazines, on postage stamps and so on. They possess historical signifi-

Fic. 1. Repeated measurement of the position of the electron in a single atom.

cance and we may take them as symbolising the success of atomic physics. But they have just about nothing whatever to do with reality. We now imagine a few experiments performed on our atoms, all depending on measurement of position. We

choose determination of position since it is easy to picture.

For reasons that will be obvious in a moment, we shall assume that all the atoms are “intact” before the beginning of each experiment, that is, that no measurements of any kind

have as yet been performed on them. Experiment (a). We select a certain atom and measure

the position of the electron. We find it at some point, in the neighbourhood of the nucleus, say at a distance of about

1/20,000,000 mm from it. We then repeat the position measurement several times with the same atom, at equal

34

MAN

AND

SCIENCE

short intervals of time. We join up the successive points so found by straight line segments (Fig. 1). What we find is a completely irregular zig-zag path. The steps are sometimes short, sometimes longer. There is no recognisable regularity. Moreover, sooner or later the zig-zag path departs from the vicinity of the nucleus. The distance becomes so

Fic. 2. First measurement of position in a large number of atoms. Statistical distribution of the position of the electron.

great that we have to say that the electron has left the nucleus, that it is no longer within the sphere of its attraction. The atom has thereby been destroyed, or in physical language, ionised by removal of an electron from the atom. Experiment (b). We choose say 100 intact atoms and carry out a preliminary position measurement on them.

In

each case we find the electron in the neighbourhood of the nucleus, but naturally not always in the same position. Most of the electrons group themselves around a distance of about 1/20,000,000 mm.

a few rather nearer.

A few are rather further away,

We can plot all the results of the

measurements on the same sheet of paper, with the nucleus at the centre, and obtain in this way a certain statistical

distribution

of the position of the electron about the

THE ATOM

35

nucleus (Fig. 2). Itis, we may remark in passing, spherically symmetrical, as is almost self-evident. If we repeat the experiment with a second serics of 100 atoms, the same statistical distribution results. This is therefore something characteristic of the atom. We have thus found a certain statistical regularity. It follows too that no definite orbit exists,

Fic. 3. Measurement of position in a large number of atoms

as in Fig. 2, but a certain interval of time has elapsed since the first measurement.

since if it did, we would not find a distribution in space,

but the electrons would always be situated on the same curve. Experiment (c). We take the same 100 atoms on which the preliminary position measurement of Experiment (b)

has been performed. These atoms are thus no longer intact. We now repeat the position measurement after a short interval of time.

Since we are dealing with the same atoms,

we might expect to obtain the same statistical distribution

as before under (b).

This is however not the case.

Of

course we again obtain a statistical distribution, but it differs

essentially from that previously obtained (Fig. 3). Itis much

more

spread out, the distances between

the electrons and

nucleus having become much larger on the average.

The

36

MAN

AND

SCIENCE

distances are greater in proportion to the time elapsing between the first and second measurements. If the second position measurement

follows immediately

after the first,

with zero time interval, the same result is always obtained, which is self-evident, since it is merely a case of confirming the first measurement.

In some

cases, when

the

second

measurement is made, the electron is already so far away

from the nucleus that we must say that the atom is ionised,

i.e. destroyed. Experiment (4).

atoms,

on each

We

of which

select a very large number of individually

we

carry

out Ex-

periment (a), that is, we determine the zig-zag paths which the electron has followed. We are not surprised to find different zig-zag paths, of the same type as in (a) but all different.

To begin with, the starting-points are in general

different, as follows from Experiment (b).

But let us now

make a narrower selection among these various zig-zag paths. Among the numerous measured paths there will certainly be many for which the initial point is the same or at least practically the same. Moreover there will certainly be a few whose first segments are about the same, for which in fact the first and second position measurements have given the same result. Since we have arbitrarily many atoms at our disposal, it is in the end only a matter of patience to find at least a few (two are enough) paths whose first segments are the same. Wechoose these and consider the subsequent course of events. It turns out that even so the continuation of the zigzag path is completely different for different atoms (Fig. 4). We shall now try to make some deductions from these observations. In the first place it is already clear from (a) that we cannot speak of a clear-cut, regular orbit; for if there was one, we would expect the first segment to be continuously repeated, developing into a polygon inscribed in a smooth curve, for example an ellipse. But there is no question what-

ever of this being so.

It is clear that to a certain extent

THE ATOM

37

chance governs the situation. Further the “orbits” if we choose so to describe the zig-zags, are different from atom to

atom. This is still the case when the first segments happen to be the same, as we have seen in Experiment (d). But the first segment

of the path would,

if Newtonian

mechanics

Fic. 4. Repeated measurements of position on two different atoms (as in Fig. 1) in which the first segments of the path happen to coincide.

held, provide precisely the initial conditions needed to predict the whole of the subsequent orbit. We would know

the initial position, and from the length of the first

segment

and the chosen

time-interval between

the two

measurements the initial velocity as well. If Newtonian mechanics were valid the subsequent orbit would be pre-

determined, and would thus of course be the same for atoms with the same initial conditions. This is however by no means the case. So the first conclusion we may draw is that the determinism of Newtonian mechanics no longer holds;

the situation, as we have said, is to a certain extent

governed by chance.

On the other hand, statistical regu-

larities hold, that is, laws relating to a large number of atoms. In Experiment (b) we met a law of this sort, in connection

38

MAN

AND

SCIENCE

with the distribution of the position of the electron in a large number of atoms when a first measurement of position is made on them. If we now ask what we can assert for a single atom, we are clearly led to the idea of probability. We cannot make a definite prediction as to where the electron will be, but at the same time the result is not com-

pletely random.

In the majority of cases the electron is

about 1/20,000,000 mm distant from the nucleus, and consequently it is most probable for a single atom that we would find the electron at this distance. There is thus a

definite probability of finding it in one position, and a different probability of finding it in another position. We

can rcad off these probabilities directly from the statistical distribution for a large number of atoms. Similarly there are probabilities for the zig-zag paths.

If the first segment is given (as in Experiment (4) above) we can say how great the probability is that the second segment should have a definite length and direction. Newtonian mechanics would give a perfectly definite result. From this

we see that in quantum mechanics statements about probability take the place of the definite deterministic predictions of classical mechanics. A further important consequence can be drawn from a

comparison of Experiments (b) and (c). The position measurement in (c) was made on the same atoms and in the same way as in (b), yet the result of (c) was quite different from (b). The sole difference between (c) and (6) is that in (c) a previous position measurement had been made, while

in (b) the atoms were intact.

It therefore follows that the

first position measurement has affected the atoms.

have

seen,

a certain number

of atoms

have

even

As we

been

destroyed by the measurement, (namely if the second position

measurement shows the electron at a great distance from the

nucleus).

What has just been said about position measurements

THE ATOM

39

also holds, mutatis mutandis, for other measurements. In general there exist only probabilities for the expected results of measurement, and cach such measurement influences the object. Of course, there are exceptions in which a measurement yields a perfectly definite, unique result, a situation particularly important for the physicist. Our two conclusions, the occurrence of probabilities and

the influencing of the object by the measurement are not logically independent. Let us try to understand them better. If in the intact atom no definite statement can be made

about the position of the electron, that is, if only statements

about probability can be made for it, we shall say that the

position is affected by an uncertainty, or indeterminate. Since in quantum

mechanics,

apart from special cases, we

can only assign probabilities for the result of measurement of

any quantity, we have in general to do with uncertain

quantities. The existence of uncertain quantities is a feature characteristic of quantum mechanics, and is of course basically new. The precise sense in which this is to be

understood will appear later.

The essential uncertainty of

quantities is the reason why determinism does not hold. If for instance position or velocity do not have sharply defined

values at the outset, then even according to Newton the subsequent orbit would not be determinate, and if vice versa there is no definite orbit, then something or other is uncertain. In Experiment (d), where it looked as if we had defined

initial position and initial velocity it will appear that in

reality this is not so at all, and that in this experiment we

have not determined and defined both quantities sharply. Here too something has remained uncertain.

So now we perform a measurement on an intact atom. The above probabilities, along with other factors, are characteristic of the state of such an atom. But the whole point and object of a position measurement is to obtain accurate knowledge of the position—otherwise it would not

40 be

MAN a measurement.

AND Hence

SCIENCE after

the

measurement

the

position of the electron is necessarily sharply defined, and its distance from the nucleus has a perfectly definite value. This is confirmed by the fact that a second position measure-

ment following immediately after the first (without any time elapsing) gives the same result. But the state of the atom has changed in consequence. Previously it was characterised by a wide probability distribution for the position of the electron; now the position has become sharply

defined. The atom will react to subsequent measurements in a correspondingly different way. Indeed as we have seen a position measurement means a very drastic interference with the atom, which in some cases can even lead to ionisation, i.e. the destruction of the atom as such.

We must now examine in more detail the change of

state caused by the measurement.

An intact atom is of

course not primarily characterised by statements about probabilities. An atom left to itself for a long time is in a sort of state of rest, like a pendulum that has ceased to oscillate. This is the state of lowest possible energy.!

Quantum theory shows that this lowest state has a perfectly

definite energy.

We have here an example of the fact that

there are quantities which can take a sharply defined value.

This energy value is negative, since the electron is bound to

the nucleus. To ionise the atom a considerable expenditure of energy is necessary. Since the position measurement may, as we have seen, ionise the atom in some cases, it is clear that a position measurement changes the energy of the atom, so that the measurement itself requires energy. There are now

two possibilities:

either the energy has, after the position

measurement, a different but well-defined value, which may 1 The comparison is defective in other respects.

rest because of friction.

A pendulum comes to

There is no friction in the atom, but an atom not in

a “state of rest”’ loses energy by radiation of light, until the lowest state is reached. “State of rest’? means not the absence of velocity, but merely the state of lowest energy.

THE ATOM

41

depend on the position found for the electron, or, since we always have to reckon with uncertainties, the energy is now

no longer sharply defined and does not have a definite value. That the second alternative is the correct one can be made

plausible as follows.

The energy of the electron consists of two parts, the

potential energy V, which is given by the reciprocal of the distance r from the nucleus (i.e. V is proportional to 1/r), and

the kinetic energy $ınv?, where m= mass, v=velocity of the electron. If the position is measured we know r and there-

fore also V. So after the position measurement Vis certainly sharply defined. If the total energy were sharply defined, 4mv? and hence also v would have to have a definite value.!

All the essential data that determine the atom would thus be well-defined, and there would be no reason why anything

should still be uncertain.

We would then have fixed the

Newtonian initial conditions, and would expect to obtain a

well-defined orbit.

But we have seen (Experiment (d)) that

we never obtain a definite orbit, no matter how hard we try to fix the necessary initial conditions by measurement. We cannot avoid the uncertainties in one form or another. After the position measurement too something must remain

uncertain or must become uncertain anew. We must therefore conclude that as a result of the position measure-

ment not only has the energy changed, but that it no longer has a sharply defined value. So the energy has been rendered uncertain by the measurement.

Since it is a question

only of the kinetic energy dmv (V is determined by the position) we can also say that after the position measurement the velocity certainly cannot have a sharply defined value.

This means that if we subsequently measure the velocity we

could obtain all possible values.

1 In the intact atom in the “state of rest” r (and therefore V) is not sharply defined since the position is uncertain; noris 4mv*. But thesum V+ dmv? has a sharply defined value. The uncertainties of V and 4mv? compensate each other. D

42

MAN

AND

SCIENCE

We have here arrived at the most important basic principle of quantum mechanics. We can measure a quantity which was uncertain, and it then becomes, by definition,

sharply defined. But the knowledge thus acquired is at the expense of the definiteness of some other quantity. Something is always uncertain. We cannot avoid the uncertainties, we can only transfer them by the measurement of one

quantity to some other quantity.

In an intact atom the

energy is sharply defined, everything elsc is uncertain. We measure the position: this becomes sharply defined, while the energy becomes uncertain. If later on we measure the energy

again, we obtain all possible values. We shall call this principle, according to which the accurate knowledge of two quantities is in principle impos-

sible, the principle of complementarity, following Bohr’s terminology. We call two quantities which cannot simultaneously be sharply defined, complementary.

In particular,

this concept will be applied to the extreme case: if one of the quantities is sharply defined, the other is “as uncertain as

possible”.

That is, all values of the other quantity are equally

probable. We know nothing at all about this latter quantity. It is not even so that at least some values are more probable than others. In this sense position and velocity are an extreme instance of complementarity (we cannot prove

this in detail here);

if the position is sharply defined the

particle can have any velocity, and all velocities have an equal chance of occurring.!

We now understand why we can never obtain a definite

predictable orbit. To do so we would have to fix the initial position and the initial velocity. But it is precisely this that is impossible, since the two data are complementary. 1 It follows from this that in Experiment (4) in which we make a second determination of position after a short interval we are not determining the initial position and velocity in the sense of the Newtonian initial conditions at all. After the second position measurement the position is again sharply defined, and hence the velocity is not known.

THE

ATOM

43

One of the two quantities is uncertain and consequently the

future motion is undetermined.

The indeterminacy of quan-

tum mechanics is the direct outcome of the principle of

complementarity.

How then are we to picture an atom, in which one or more quantities are uncertain? And of what nature are the

laws that hold in an atom?

If things like position or velocity

of an electron, of which we can form a concrete picture, are uncertain, it is clear that we can hardly form a picture

of the atom in space and time or of the motion of its electrons. The laws concerned must be of a very abstract kind. Let us think of an atom in any particular state, say in the

lowest state, the state of rest.

It might also be some other

state, of higher, but sharply defined, energy, produced, let us

say, by collision of the atom with other atoms or by absorption of light. It might also be a state produced artificially by making a position or other measurement.

The atom in its

momentary state is characterised by two things. Firstly, the sharply defined value of one quantity, the energy (in the

state of rest or higher state) or the position of the electron after the measurement, or some other quantity. The second

characteristic of the state is probabilities, the probabilities

with which the various results of measurement are to be

expected in a future measurement of any quantity.

The laws of quantum two things: the sharply and which are found in a with which the different

mechanics have reference to these defined values a quantity can take measurement, and the probabilities values occur when a measurement

is made. The laws do not in any way refer to anything that takes place in space and time, such as for example motion in

an orbit, but to rather abstract things, probabilities, which

have meaning and significance and can be understood only in the language of mathematics.

The laws allow us to predict accurately the values a

44

MAN

AND

SCIENCE

quantity can take, and also the probabilities we have mentioned, just as in classical mechanics we can predict the orbit.

Suppose we start from a particular state characterised as

above.

In general the state will change in course of time,

unless it be the state of rest of the atom, which does not

change spontancously. What is it that changes? Just all those features change that characterise the state. A quantity that was sharply defined at one moment will no longer be so

at a later time (if the position is measured at any instant it

will be uncertain again later on, as we saw in Experiments

(a) and (d)); and the probabilities also change in course of time.

For this change strict laws hold, and the remarkable

thing is that these laws are also strictly deterministic, as long

as nO measurement is made. The future state follows from the present with mathematical precision. This determinism is however fundamentally different from that of classical physics,

because

it refers

to

quite

abstract

mathematical

constructs, not to what happens in space and time. The deterministic development of the state in time proceeds until a measurement is made. This alters the state

radically. The quantity measured becomes sharply defined, and thereby a completely new state is brought into being. The continuous causal chain of development of the state is interrupted, in a completely unforeseeable way, because the result of the measurement cannot be accurately foreseen.

This is the point at which indeterminacy comes in; thus it comes in exactly at the point where we compel this abstract construct,

the atom,

by means

of a measurement,

position, to manifest itself in ordinary space.

e.g. of

When

we

have done this the spatial picture (e.g. a definite position for the electron) does not persist, but the measured quantity in

general becomes uncertain again directly afterwards. Thus the laws of quantum mechanics possess a degree of mathematical abstractness far beyond what we are familiar with in classical physics. Classical physics also requires, to

THE

ATOM

45

put it in popular terms, higher and indeed the highest mathematics.

Newton invented the infinitesimal calculus

for the express purpose of formulating his laws conveniently.

(The calculus was also invented independently by Leibniz,

without reference to physics.) But the laws of electrodynamics, light and especially the theory of relativity

demand substantially more. For all their mathematical sophistication, however, the classical laws always deal with things that happen in space and time, and can be measured

directly. Thus the electromagnetic field is something that is propagated in space and can be measured at every point of space, and the laws deal directly with this field. It is different in quantum mechanics. The laws deal with probabilities, that is, with something that has no reference at all to

ordinary space, and moreover cannot be measured in any

way in an individual atom.!

In order to test them and make

use of them in physics, we have to experiment with many

atoms.

But ourconsiderations refer to the single object.

The

single atom is thus an object of a very abstract character that

does not admit of a complete description in space and time.

We must draw a further conclusion from what has been said, of great importance for our present purpose. Let us look still more closely at what we call a "measurement. Consider once more an atom;

ment on it.

let us carry out a measure-

To keep things simple, assume that there are

only two possible values, a and 6, for the measured quantity

(such cases do exist). Let the probabilities with which we may expect the two values be vw, andw,. Their sum must of

course be equal to unity, w,+w,=1, since one of the two values must certainly eventuate. Further consequences will

1 More precisely, the laws of quantum mechanics do not even deal directly with probabilities, but with still more abstract mathematical concepts from which the probabilities are obtained by further mathematical manipulation. The reader who knows some quantum mechanics will recognise that we are referring to the probability amplitudes, of which the wave function is a special case.

46

MAN

AND

SCIENCE

of course follow from the result of the measurement.

Still

keeping things as simple as possible, we shall further assume

that another quantity certainly takes the value x=1

if the

result of the measurement is a, and the value x=2 if it is b.

We had a simple example in the measurement of position and the destruction of the atom. If the distance of the

electron from the nucleus should turn out to be very large (say greater than a definite value, result, a) then it is certain

that the atom has been destroyed (corresponding to x=1).

If on the other hand the distance is small (smaller than the particular value above, result b) the atom is not destroyed (corresponding to x=2). We now make the measurement

— we switch on the measuring apparatus.

But we do not as

yet trouble to read off the result; or we take a photograph, but do not develop the plate.

The measurement has been

in a sense completed and the plate undoubtedly shows the value a or b, but we do not yet know which. We now ask

if we can already say anything about x. We

cannot yet know

whether x=1

Clearly not as yet.

or x=2.

All we can

say is that the probability of a resulting is w,, and conse-

quently, since x=1 necessarily follows from a, that the probability for x=1 is equal to w, and that for x=2 is w,. It is

different if we read off the result of the measurement. If we have found a we also know for certain that x= 1 and that the probability for x=2 is zero. Thus it is clear that we can speak of a measurement as fully made and completed, with

all that it implies, only if we consciously take cognisance of the result. This is a perfectly simple and obvious conse-

quence of the occurrence of probabilities. It is just like casting dice and knowing that if we throw a 6 we stand to win {100. If we make a throw without looking at and taking cognisance of the result it would certainly be rash to regard {100 as already at our disposal. It is essential that the observer should take conscious cognisance of the result of measurement. In the whole

THE

ATOM

logical structure of quantum observer plays an essential part.

47

mechanics the conscious Man, in so far as he is an

observer,

can no longer

be ignored.

In this respect also

physics.

There events do not depend on whether anyone

there is a fundamental difference as compared with classical observes them or not. The moon moves in its orbit whether we are looking at it or not. Physical processes are completely detached from man. In the physics of the small-

est systems, the physics of the atom, it is different.

case, as soon

what happens;

as we

observe

what

happens

a new state is produced.

we

In this

also affect

But what the

influence is, that is, which measured result is obtained is known only after we have consciously taken cognisance of

the result of the measurement.

Until this has been done we

can only say that we have influenced the object, but we do not know how.!

However, the physicist scarcely gets to the point where all this comes in. He is interested in laws, indeed in quantita-

tive laws. But these manifest themselves in the first place in a statistical manner. To test probabilities experimentally he has to repeat the same measurement on many single objects. Here as before quantitative laws hold. A certain measure of determinism also holds. The probabilities can be calculated in advance, and therefore also the statistics of the results of measurement of many identical atoms. When in the following chapters we use the expression “causal or deterministic science” in this wider sense, quantum mechanics is meant to be included, in view of the facts we have

just described. It is clear that quantum mechanics, classical physics, also has a quantitative character.

like

1 To understand the considerable influence exerted on a small object by measurement it is essential to realise that large measuring devices, of macroscopic dimensions, are requisite. The smaller the object the larger and more massive the measuring apparatus has to be. For the investigation of the interior of the nucleus large machines are required—the great particle accelerators, of the dimensions of a factory.

48

MAN

AND

SCIENCE

None the less the significance of quantum mechanics for the philosophy of science can scarcely be overrated. For we

may be interested in a single object, even if this is less useful for

the

physicist,

and

in this

case

the

non-deterministic

situation described in this chapter obtains. Let us first summarise it briefly. A single atom cannot be directly pictured in space and time, but can only be described by using abstract mathe-

matical concepts, e.g. probabilities.

Being of this nature, it

behaves in a causal and deterministic way just so long as no measurements are made on it. A measurement compels the atom, so to speak, to manifest itself in space and time.

The

result is an essential indeterminism. The spatio-temporal data (the results of measurement) no longer obey deterministic laws. They are essentially uncertain quantities which become sharply defined only through measurement. The situation is one of complementarity, which in general does not permit of several quantities simultaneously becoming sharply defined. If one quantity is made sharply defined by a measurement, another quantity becomes uncertain in consequence. In subsequent measurements there are only probabilities for the latter. To be complete, the measurement includes the act on the part of a conscious being, the “observer’’, of taking cognisance of the result. The observer can therefore no longer be sharply separated from his object. The philosophical and epistemological consequences arising from quantum mechanics do not seem to have been exhaustively followed up. For this we shall probably have to wait a long time.

Quantum mechanics does not fit into

any philosophical scheme or “-ism”. This follows from the fact that it has been claimed by materialism as well as by positivism, and has also been maligned as an idealistic theory. However, a few definite assertions can be made, and obvious

conjectures and questions arise. In the first place it is clear that the philosophy which

THE ATOM

49

regards the world fundamentally as a mechanism running on deterministic lines (a view which we have already criticised in the first two chapters) is deprived of its very foundations. Classical physics provided the prototype for a mechanism of this sort, while other sciences, including to a large extent

biology, followed suit. Physics itself has again abandoned this picture in regard to the world of the atom. Will other sciences follow? It is not very surprising that man, as a conscious observer,

again comes into the picture. For we have already seen how difficult it is to draw a sharp unambiguous line between object and subject. Classical physics was able to make the division in a clear-cut if arbitrary way, at a price. The price was all that is qualitative, all that is not expressible by measure and number. In atomic physics even this is no longer possible. The observer has become indispensable; a clear-cut separation of the external world from the observer is not possible as soon as any observations whatever are made; for these influence the object in an unpredictable way. Why the impossibility of separating object and subject should first appear just in the physics of the smallest particles is a question we cannot answer.

We can only say

that if it were different, if, for example, quantum mechanics

held for the macroscopic quantities of our surroundings, we

could have no conception at all of an external world apart from ourselves. The logical mode of thought we have described by the word complementarity replaces the causal logic of classical physics. It is a mode of thought that is completely new and has found application probably for the first time in quantum mechanics. We may surely expect it to prove fertile elsewhere as well. In the next chapter we shall meet with another application, although so far it is of a very speculative nature. We need not waste words on the success of quantum

40

MAN

AND

SCIENCE

mechanics, whether in the sense of pure knowledge about

nature, or of applications.

There is one point however to

which we would like to refer in this connection. Quantum mechanics is valid—it seems obvious to us nowadays—not

only for atoms, but also for molecules, the province of chemistry. In this way two sciences that previously led separate unconnccted existences have been fused into one. It is precisely the most

important

facts of chemistry,

the

combination of atoms into molecules, chemical reactions and much else that have been seen to be consequences of

quantum mechanics. The validity of quantum mechanics will be extended to the large molecules of organic chemistry

as well, and in this field much good work has already been done. With the very large molecules, the macromolecules,

we pass into the realm of biochemistry and general biology,

which forms the subject of the next chapter.

We shall see

that important vital functions depend on such individual

macromolecules. The fact that quantum-mechanical than classical laws hold in this field cannot but be of mental significance. Finally we would like to add some remarks “mathematical abstractness’’ of quantum mechanics, modern physics in general. The further physics advances the greater does the

rather funda-

on the and of degree

of abstraction become and the “higher” the mathematics it

demands. In atomic physics a degree of abstraction has been reached that represents the reality of the atom itself as

an abstract structure that cannot be pictured in space, but only described mathematically. Only “with difficulty’,

namely by the drastic intervention of a measurement, can this structure be forced into a concrete spatial picture,

which moreover subsists only for a moment immediately after the measurement. Mathematics is not a natural science.

Mathematical

relations and laws are not material in nature, and are not to

THE

ATOM

be equated to a physical process.

41

At first sisht mathematics

appears as a pure creation of the human intellect, comparable

rather with a work of art. Many branches of mathematics were created long before physics needed them, by “pure

mathematicians’, who never dreamt of any connection with

nature, some of whom indeed refused to consider any such connection.!

What can this product of our own intellect

have to do with the world around us and its laws, with the

external world which is said to be completely detached from

and independent of man? Looked at in this way it would be a completely incomprehensible miracle if the world should obey laws expressible only by means of the mathematics we have ourselves invented.

Our cannot classical govern

mental activity and the external physical world be as independent of each other as this. Even physics with the complex mathematical laws that its course forces us to the conclusion that our intel-

ligence is somehow very intimately bound up with this external world. It is this connection that allows us to recog-

nise these laws at all.

We can hardly assume that a planet

knows the nature of a geodesic in Riemannian geometry on

which it has to move and indeed demonstrably does move.? How

does it come

about that it moves

according to such

complex and deep mathematical laws? In one way or another the conclusion is inescapable that there also exists outside of us something of the nature of intelligence—some spiritual principle*—associated both with the laws and events 1 Two of the most perfect examples are non-Euclidean geometry, and later Riemannian geometry, which is the foundation of the theory of relativity; and group theory, which has become basic for quantum mechanics and the modern theory of elementary particles. 2 The law of the geodesic has of late replaced Newton’s laws of motion. For readers to whom these concepts are without meaning it will suffice to imagine concepts of very high mathematics. 3 “Ein geistiges Prinzip”. The German word “geistig”, unlike the word “spiritual” used here and subsequently as a rough equivalent, does not carry a religious overtone.—Translator.

52

MAN

AND

SCIENCE

of the material world and with our mental activity. And so we are brought to the borders of metaphysics. We said just now “outside of man’. This of course again assumes that a boundary can be drawn between outside

and inside.

But we already know (Chapter 2) how difficult

it is to draw such a line.

Even in the realm of sense percep-

tions it can scarcely be drawn unambiguously.

Here, in the

purely mental sphere, it is probably much more difficult. On the other hand what we are concerned with is something

that bears a relation to the external material world, and is not

subject, or is only partly subject, to arbitrary choice on our

part. We did not invent the laws of physics, although our mental activity plays an indispensable part in their discovery.

This must serve as a justification of the term “extra-human principle”. Without committing ourselves on points of detail, it may help us to understand something of what this could involve if we refer to Plato’s philosophy, in particular to his

doctrine of ideas. Mathematical concepts and discoveries arise through mental processes most readily described as intuition, preceded by more or less intensive thought.

Although observation and experiment act as a stimulus, it is never by these means alone that physical laws are recognised. The final step, the recognition and formulation of the law likewise depends on intuition. In the material world

around us there is no such thing as a geometrical point or a geometrical figure, nor is any physical law satisfied with mathematical exactitude. Both are conceptual constructs,

thought-structures,

and there is nothing

in the material

world with which they are completely identical.

Plato’s

philosophy conceives of the intuitive apprehension of these

concepts and laws as a form of perception—perception of “ideas” that exist outside ourselves, and in which the forms

of pure geometry are pre-figured; and we may include the purely physical laws as well, these being unknown in Plato’s

THE

time.

ATOM

43

These Platonic “ideas”! are operative in the material

world apprehended by the senses, but here they are never realised completely and in perfectly pure form. They give rise to phenomena,

forms

of motion

and

so on,

which

correspond more or less closely, but never quite accurately to the “original” i.e. the pure law. But in our intuitive grasp of concepts and laws we can “apprehend” them in pure form.

Yet in classical physics the object is something per-

ceptible to the senses, or manifests itself through the senses;

at all events it can be thought of and described in ordinary space (e.g. the electromagnetic field). When we inquired how

it comes

about that it obeys complex

and abstract

mathematical laws we were led to the above metaphysical considerations. The individual atom cannot even be pictured in space and time. Even a bare description of it demands profound mathematical concepts. So it can hardly be thought of as something of a purely material nature;

its

“mathematical aspect’’, that is, its non-material aspect, is even more strikingly prominent than is the case with an object of classical physics. There is every indication that in the future

progress of physics this tendency will grow. In view of this fact we cannot avoid putting special stress on the above metaphysical considerations. Of course we have no intention of committing ourselves to Plato’s doctrine of ideas in all its details. What the fore-

going observations amount to is that physics, and particularly atomic physics already poses metaphysical questions. These ought to be answered before a philosophy of science

can be based on physics. further

investigations,

We shall not be surprised if in our

which

are concerned

with

biology

and cosmology, we also encounter metaphysical problems. 1 Plato uses the word

“idea” not in the modern

sense of “spiritual prototype”.

sense but rather in the

Chapter 4

The Science of Living Things HE author is a physicist and not a biologist.

Perhaps

some readers will say he is not entitled to write on a subject in which he is not an “expert”. But the questions to be dealt with here are concerned with the

borderline

between

the

exact

sciences

of physics

and

chemistry on one hand and of biology on the other, above all the question of how far physical and chemical laws are

capable of explaining vital processes. must have his say.

And here the physicist

Modern biology is also tending strongly in the direction of the causal and quantitative. This is unmistakably shown

by the birth of two new sciences, biochemistry and bio-

physics.

The

attempt

is being

made,

not

without

con-

siderable success, to investigate physical and chemical processes in living bodies, and then to reduce typical vital

processes to a physico-chemical mechanism. But is this all? Can a basic understanding of vital processes be reached through physical laws? Far be it from us

—let there be no mistake—to

minimise the great achieve-

ments of this causally and quantitatively orientated biology, achievements which will doubtless be even greater in the future. All the same we must put the question as one of principle, and try to answer it. We shall consider three typical vital phenomena and test the possibility of reducing them to purely physical and

chemical facts. (1) Form and size of the living body and of its separate organs; (2) evolution, the historical development 54

THE

SCIENCE

OF LIVING

THINGS

55

of higher organisms out of lower; (3) the existence of consciousness in animals and in man.

Every living organism is characterised by a perfectly

definite form and size of its separate organs.

The leaves of

any particular plant all have the same shape (for example with a serrated edge) which is not by any means a simple geometrical figure. Their size in the fully developed

healthy state varies within narrow limits, say for instance

between 5 and 1ocm.

There are no fully developed leaves

in this plant as small as ı mm. or as large as ı m. The same holds for the thumb of a monkey’s hand, for the internal

organs, and so on.

The size is of the order of centimetres,

not of molecular dimensions, nor is it of the order of magnitude of an individual living cell. The properties of size and form are inherited and transmissible.

Let us now go back to the original process of generation of such a living organism. It begins with the two germ cells, male and female. The science of heredity, which has a

splendid record of progress in recent times, has shown that hereditary qualities are localised in the chromosomes. These

are small bodies, more or less rod-shaped just before the cell

divides, which are found in the nucleus of each cell and of which there is, for each type of living organism, a definite

number, a few in the lower organisms up to about fifty in the higher. In the higher animals the germ cells each contain half the total number so that after fertilisation the right number is present. Individual hereditary properties are moreover localised within the chromosomes, in the genes.

A gene is probably scarcely bigger than a single though very large molecule. To give an idea of what is involved from the point of view of chemistry we may briefly mention one very recent result of chemical research on chromosomes. The principal constituent of the chromosomes is the so-

called DNA

(short for deoxyribonucleic acid).

This has a

very long molecule, consisting of roughly 10,000 members

46

MAN

linked in a chain.

AND

SCIENCE

It seems that there are only four different

kinds of links, which can however be arranged in com-

pletely different orders—there is an enormous number of possible arrangements. A single link contains roughly twenty or thirty atoms. The details of the relation of the DNA molecule to the individual genes has not yet been determined with certainty. But we are not concerned with the details here. We shall in any case not be far wrong in saying that individual hereditary qualities take us into the domain of such macromolecules. It is undoubtedly of fundamental significance that the laws of quantum mechanics hold here, and not those of classical physics, although this significance is not as yet perfectly clear. Looking at the chromosome chemically, all we see is an immensely

complicated

arrangement

of atoms,

held

to-

gether by physical forces, with correspondingly complicated

reactions, which however depend on the physical laws of

quantum mechanics; and the hereditary qualities are written into these chromosomes. The cell now begins to divide. The chromosome reproduces itself exactly, and exactly once. It is built up again from the material of its surroundings (mostly proteins) in exactly the same way. This process is already very hard to understand physically. No such example of self-reproduction is known in the physics and chemistry of inanimate matter. Regarded chemically the DNA molecule is not fundamentally different from any other large molecule that cannot reproduce itself. But we do not wish to commit ourselves on the impossibility of understanding a process of this kind physically. There is a further point which is perhaps of greater significance than is generally admitted. The physicist has fundamental laws which allow him “in principle” to calculate the properties and reactions of an arbitrary molecule. But the equations can be solved accurately or in a reasonably reliable approximation only if

THE

SCIENCE

OF

LIVING

THINGS

47

we have to do with a small molecule consisting of only a few

nuclei and electrons, or with a large but regularly built

system, such as for example a crystal or a long paraffin chain (this is being optimistic). The reactions of a macromolecule like DNA can certainly not be treated exactly by quantum

mechanics, any more than a waterfall can be treated by Newtonian mechanics. Not even electronic computers are

capable of this. We are inclined to regard it as an unfortunate circumstance that our limited brain-power is unable to solve such complicated problems when in principle! everything is determinate. It is not impossible that this circumstance has a deeper and more fundamental significance than merely the impraticability of too difficult mathematics. But here again we are not going to commit ourselves. So let us suppose that the multiplication of the chromosomes can be explained on physico-chemical lines. Cell-division proceeds,

a thousand

or a million times.

The single parts of the body and the organs are differentiated, each part grows further by cell division until the prescribed size and the correct form are attained. The number of cells that must aggregate together in an organ is of course very large. It is the fact of the termination of growth at a finite point when the predetermined form is attained that is so incomprehensible physically. The laws of physics are without exception differential. This means that they are effective only from any one point to points in its immediate neighbourhood and only for the immediately succeeding instant. Laws which operate at a distance, spatially or temporally, do not exist. So even though cell division might

be physically comprehensible,

as we

shall

1“In principle” is an expression physicists are fond of using; it is meaningful if something is impossible in principle, as for instance the simultaneous determination of position and velocity in quantum mechanics; but it has little meaning when used in the positive sense that something is possible in principle, but there is no way in practice, and no prospect of any way of realising the possibility. At all events such a statement would be very hypothetical.

58

MAN

AND

SCIENCE

assume it is, but which is very doubtful, then it is really

incomprehensible why and how, after many thousands of repetitions it should come to a stop, and moreover in such a

way that a perfectly definite form—a serrated leaf—results. The “information” about form and size is already contained

in the original chromosomes of the germ cells. There is nothing at all comparable in the physics of inanimate matter, a portion of which can assume any shape or size. A leaf

cut into pieces ceases to be a healthy leaf. Our picture is still greatly simplified. For the cells destined to belong to different organs develop differently and assume different functions. It seems highly unlikely that purely physical laws can bring all this about. Of course our arguments do not have the force of a strict proof, nor will such a proof be forthcoming for a long time. For we have pointed out above that it is impossible to apply the laws of physics in detail to

such processes, partly molecular, partly macroscopic (on the

scale of the fully grown organism).

For the same reason it

will also be impossible to produce a disproof.

We cannot hope to derive physically, for instance from

the molecular structure of the chromosomes—assuming that

we could determine this completely—the final form and size of the separate organs. So the conclusion we come to is this.

We will never

understand the morphology of the living organism if we restrict ourselves to the use of physical and chemical laws only. By “understanding” we of course mean substantially more than describing and classifying processes and forms.

Presumably causal and quantitative methods, including quantum mechanics, will not suffice. A living cell is already a whole, and consists not merely of 1 Sometimes when a crystal separates out of a solution geometrical forms arise in the process, for physical reasons. This depends on the crystal structure. But it is possible to produce a crystal of any desired shape without its ceasing to be chemically the same crystal.

THE

SCIENCE

OF

LIVING

THINGS

a number of juxtaposed macromolecules.

and not and the the

40

A living organ,

still more a living organism forms a whole and consists merely of a large number of cells—a whole in size, form function. Clearly cell division is primarily determined by “over-all plan” of the organ to be produced, and for this causal development from one stage to the next plays a

less important role. If we are really to understand anything of morphology we will have to proceed by a completely

new and different route and create new concepts in which the wholeness of the organism and of the whole body play a

fundamental part. unknown.

So far such a route is almost completely

This is a long way from being a violation of the laws of causality. For we have seen in Chapter 1 that by themselves these laws determine only the possible courses that events

may take.

It is only when the initial conditions are given

that the course is uniquely fixed.

But we shall never be

able to understand the morphology of the living body by their aid.

In place of initial conditions there could be a sort

of over-all plan, such as Kepler had in mind with his har-

monies. In physics the law of causality plays the dominant role, indeed the only role according to modern ideas—

unless indeed we are thinking of a machine constructed by a human being, which of course has an over-all plan. In biology it is presumably the other way round. The form of the living body necessarily points to something whole, and

it is the plan of this whole that performs a guiding role in the detailed processes also, such as cell-division. In passing we may remark that the idea of wholeness could come in even in connection with inanimate matter. A piece of copper or a crystal is not merely an arrangement of numerous atomic nuclei and electrons. For our senses

and our consciousness these bodies are something quite different.

We have seen in Chapter 2 from the example of

colour that we cannot simply gloss over our sensation of it

60

MAN

as a psychological essential.!

AND

SCIENCE

effect without

sacrificing something

A further very remakable property of the living body,

which is no doubt also connected with its wholeness, is its

extraordinary stabilityin regard to decay.

There is a general

physical law applicable to bodies consisting of many atoms or molecules—the law of increasing entropy. A body of this sort always tends to come to the temperature of its surround-

ings. Similarly differences of pressure are smoothed out. Chemical transformations take place in such a way that in general simple stable molecules result. Entropy is a quantitative measure of this state of uniformity. The maximum of entropy is attained when everything has been smoothed out in the body and the chemical reactions have taken place. The

body is then in a state of equilibrium with its surroundings. Nothing further happens, either physically or chemically. The law does not however say anything about the rate at which this final state of equilibrium is reached. The living body must clearly have very low entropy. It maintains itself (at least in the higher animals) at a tempera-

ture different from that of the surroundings, and above all

consists of highly complex chemical molecules. That these by no means correspond to the maximum of the entropy

can be seen as follows.

To kill a living body a very small

change, physically speaking, is sufficient.

We have only to

sever a few nerve fibres at a critical spot or destroy a few vital brain cells. These are changes that scarcely matter

physically and give rise to no essential change of entropy. But then decomposition immediately sets in under the influence

of

the

surroundings,

the

complex

molecules

break up, and so forth. Moreover the process of decomposition sets in at all points of the body. The dead body immediately tends towards greater entropy. Clearly therefore 1 Here again we may cite the short essay by M. Born (p. 15) in which he avows his adherence to “Gestalt” philosophy.

THE

SCIENCE

OF

LIVING

THINGS

61

there is in the living body some force that offers a resistance to this decay (under the influence of this same environment). Of course no violation of the law of entropy itself is involved;

for this does not say anything about the

rate of decay. The body however posscsses the capacity of keeping its entropy low throughout its whole life. This holds for all parts of the body which are asscciated with the life of the whole. This force of resistance is thus something that fills the whole living body and constitutes a fundamental distinction between the living and the non-living.! In the second place let us consider evolution. We take it as basic that living organisms have in course of time developed from lower, that is, relatively simply constructed forms into

higher, more development man is given development there were retrograde

complex forms. The period of time for this from the most primitive living organisms to as roughly as 100 to 1000 million years. The certainly did not follow a steadily rising line;

mistakes,

Nature

development,

made

false steps;

phenomena

of

and also

degeneration.

Whole species, at one time masters of the earth, have be-

come extinct in their turn.

We shall not discuss in any

detail that part of the Darwinian thesis which states that

“better” developed species are more efficient in the struggle for existence, and so suppress other less efficient species. How great a part this principle of selection plays in evolution is a question which we shall leave entirely open. We shall not discuss at all the problem of the origin of the first living cell—perhaps from non-living matter. Absolutely nothing is known about this; there is not even a useful hypothesis. The one question we shall ask and discuss is how do higher organisms develop from lower organisms? It is 1 There is no doubt that the law of increasing entropy is satisfied in the living body. In the full-grown state the entropy remains more or less constant. In the growth stage however the amount of matter with low entropy is increasing, but this is amply compensated by food intake and respiration.

62

MAN

AND

SCIENCE

probable that this development took place by more or less discontinuous stages. There are indeed intermediate steps between different species now extant, but no really continu-

ous transition. The devclopment must therefore have involved a morc or less discontinuous element.! It will be well to link our discussion with a theory held

by many biologists.

This theory rests on the existence of

mutations in a particular species.

Mutations

are more

or

less essential changes occurring suddenly in the body struc-

ture of the species, whose chief property is that they are transmissible.

For instance it might be a matter of colour

of limbs, etc.

Some gross defects are also of this nature, such

change in the wings of insects, or small changes in the shape as missing limbs, etc. colour blindness

In the case of man, haemophilia and

are relatively frequent mutations,

are transmitted according to perfectly definite laws.

which

Mutations often occur spontaneously, in which case they

first appear in the progeny of a particular pair of parents.

But they can also be produced artificially by irradiation of the germ cells with X-rays or rays from radioactive bodies,

and also by chemical influences.

This is one of the reasons

why radioactivity is so extraordinarily dangerous, not only

for the organisms exposed to it but also for their progeny. It is quite possible that spontaneous

mutations are due, at

tions,

intervention

least in part, to the same causes as artificially induced mutasince

even

without

human

we

are

exposed to weak radioactivity from the earth’s crust as well as to cosmic radiation. All these mutations are harmful or at best—as in the case of insignificant colour changes—neutral. In many cases

!It is possible that while there is a continuous transition between different stable species, the intermediate stages are traversed relatively rapidly, so that they do not survive into the present. Or it is possible that present species are branches of a common unobserved stock; but in this case too a more or less discontinuous element must enter at some point. However this may be, the matter is not essential for the following discussion.

THE

SCIENCE

OF LIVING

THINGS

63

severe damage is involved, leading even to stillbirth It is fairly certain that these mutations are due to structural changes in the chromosomes. A change of this kind under the influence of e.g. a quantum of X-rays on a macromolecule of a gene would not be difficult to understand with the

help of quantum theory.

Mutations arising in this way are

governed largely by chance. Whether a mutation will occur, and what mutation, depends on what particular microscopic point of the chromosome is hit by the X-ray and what change it induces in the gene. As molecular changes are involved, the indeterminism of quantum

mechanics comes in.

The physical changes that an X-ray

quantum causes in a molecule are also determined by laws of probability. This is an additional chance element in the origin of mutations. The theory we are speaking of assumes that among the numerous mutations that occur, most of which are harmful,

there will occasionally, even though very rarely, be favourable ones which imply development of the living organism

to a higher form.

Since the mutation is transmissible, these

more highly developed organisms will spread and succeed in the struggle for existence. According to the Darwinian prin-

ciple of selection harmful mutations are of course immediately

eliminated.

This hypothesis is called Neo-Darwinism.

This theory

follows the main stream of the idea of

causality, with chance playing a part, as always in complex processes. The random element is due (if we accept the above detailed picture) in part to the essentially random element in quantum mechanics, but also in part to our inability to tell precisely when and where an X-ray quantum

1 Reports from Japan on human mutations induced by the radioactivity of the atomic bombs are contradictory. One report (Midwives’ Con-

ference,

1954)

asserts

that

about

fifteen

per

cent

of the offspring

of

parents who had been exposed to the radiation exhibit severe damage. Other reports, issued by special research stations, on the consequences of

irradiation, do not mention mutations at all.

64

MAN

AND

SCIENCE

registers a hit. The latter is not randomness in principle, but is random to the same extent as the place where the first raindrop falls from a cloud. It is certainly a very plausible theory—until we consider all that is involved in a “chance” of this sort. A higher mammal is determined by an enormous number of factors. All the bones, muscles, tendons, nerves and other organs are fairly accurately determined as to position, size and shape. We are for the moment disregarding completely the refinement and complexity of internal structure of these parts of the body. How many factors alone (relating to muscles, limbs, nerves) are needed merely to enable the squirrel to carry out its incredibly surefooted climbing feats? We shall leave instinctive aptitude entirely out of account. If even one of the essential determining factors in the mutation had “come out wrong” the whole thing would not work. The probability that all this does come out right by chance is so fantastically small that we could not expect to find a squirrel once in the whole course of the evolution of life. It scarcely matters whether the mutations leading to the squirrel took place in one large step in which several determining factors changed at the same time, or in

a large number of small steps. This recalls examples such as the well-known puzzle whether even the first line of Hamlet’s soliloquy could arise by a chance arrangement of letters. It is desirable that we should get a clear picture of the improbability of such a chance. The first line of Hamlet’s soliloquy consists of thirty letters, of which a, q, r, u, each

occur once, b, h, i, n, s, each twice, e four times, o five times

and t seven times. Let us take these letters out of a type-case (the letters themselves are already determined) and arrange them repeatedly according to blind chance until we obtain the right arrangement. We would have to make nearly

10”, that is, nearly a billion billion trials before having a

single chance of finding the correct arrangement.

(We use

THE

SCIENCE

OF LIVING

THINGS

65

the European billion, not the American billion;

ı European

billion = ı million million.)

Of course this example has no

direct connection with mutations. But consider the DNA molecule described above, the main constituent of the chromosomes, with its 10,000 links, in which four different

types occur in various arrangements. If it is the case (which is scarcely certain as yet) that hereditary properties are located in the DNA

molecules,

these properties can be

expressed only in different arrangements. And if for instance we assume that the mutation requisite for an upward step in evolution needs a particular re-arrangement of only 32 links in a single DNA molecule—this is certainly not

asking too much—then we have just about arrived at the above example. Assuming that the 32 links of the chain contain 8 of each type we get for the odds of a particular

arrangement

1:10!7,

that is, one

to

a hundred thousand

billion (a few zeros more or less really hardly matter).

However we look at it—we shall discuss another com-

parison later on—the extraordinary complexity of the bodystructure of the higher animals absolutely excludes chance evolution. And the more closely we study the structure of

the body, the more complex it turns out to be and the more

unlikely does “chance” become. So evolution does not depend on chance.

Hence the

possibility of understanding evolution solely on the basis of physico-chemical laws falls to the ground; for these laws always contain, in the case of so complex a structure, at least

the essential but chance element of the initial conditions. As we have already said this does not mean that causal laws

lose their validity.

But if evolution is not governed by

chance there must have been or must be some kind of plan. It is after all obvious that the squirrel is constructed in the way it is in order it may perform its climbing feats. Evolution, even more than morphology, forces us to invoke tele-

ological considerations.

This is not to say that teleology

66

MAN

AND

SCIENCE

combined with causal laws will suffice for an understanding

of life.

Much more will certainly be involved, but mean-

while let us keep to teleology, which is in any case scarcely to be avoided. We have repeatedly referred to the possi-

bility of teleological arguments as a constituent part of exact science. They have in fact been used constantly and in various ways. Leaving aside primitive views of nature ("the lion has strong teeth in order that . . .᾽ the biologist uses

them in the first place when he wants to know the function of an organ. He must enquire what purpose the organ serves. But the modern tendency is to regard this merely as an intermediate step which will lead by degrees to the causal mechanism which explains the function of the organ. As we have already remarked in Chapter 1, the chief

objection to a teleologically oriented science lies in the metaphysical implications. In testing the possibility of

teleology taking a fundamental place in science it will be

well to distinguish two separate groups of problems, namely

the purely teleological situations and regularities (if we may use this expression here too), and the more metaphysical implications connected with them. Archaeology affords a

good illustration of these two problems. The archaeologist investigating a prehistoric structure and wanting to reconstruct it makes use—as a matter of

course—of teleological arguments.

First of all he asks what

was the purpose of the chamber, or portion ofa ditch, whose ground-plan is before him. His task is easy, for he can take

it that the building was used by men to some extent like ourselves. Having solved these questions he is often able to reconstruct the building. He can then consider the second,

wider question as to the builder. He can draw conclusions as to his technical skills, his geometrical knowledge, his artistic taste. Here too he is helped by the fact that the builder was a man with abilities comparable with our own.

In biology both problems are incomparably more diffi-

THE

SCIENCE

OF LIVING

THINGS

67

cult. We cannot assume at the outset that “suitability for a purpose” is suitability in the same sense as a machine is suitable for our use; let alone that the “architect” of living organisms possessed capabilities similar to those of man.

It

is precisely all this that must be the aim of unprejudiced research. The word teleology is to be understood throughout in a fairly general sense, not only in the sense of purpose and aim but in general whenever some sort of over-all plan

is involved, e.g., a form to be fashioned. And above all no scale of values is implied. The over-all plan does not have to appear, as judged by us, as “suitable for a purpose”.

To begin with, we can limit ourselves to the first step.

We will ask questions not only about the suitability of the

structure of organs, bones and so on, for their purpose, but

will also ask how cell-division is governed by the over-all

plan of the organ to be formed, what kind of conformity

with a plan there was (and perhaps is) in evolution,! and a

thousand other questions.

There is no reason why research

so directed should not be just as “scientific” as the pursuit of

causal laws, and be on a footing of complete equality with that pursuit.

In both cases we limit ourselves to the determi-

nation of the facts, whether they are according to the plan or

are causal.

The second step, the question as to the being that made

the plan, takes us, it is true, into metaphysics.

This is how-

ever not in itself an argument against teleology as such.

Causal laws do the same. As we have already remarked in the previous chapter the laws of physics are of exquisite mathematical abstractness and beauty. We need only think of quantum

mechanics

or

general

relativity,

which

recently replaced the laws of gravity and of motion.

has

We

1 A very interesting account of evolution is to be found in the book by

the Jesuit While we for us in followed

palaeontologist Teilhard de Chardin, “Le Phénomene Humain”’. do not have to agree with everything in this book, it is important one respect; the author leaves no doubt that evolution has a planned course, with digressions and unsuccessful attempts.

68

MAN

AND

SCIENCE

have alrcady concluded from this that there must exist outside man a spiritual principle with which the laws of nature as well as our own mathematical knowledge of them are

bound up. But if we have already to recognise an extrahuman spiritual principle in the context of causal laws, then there is no difficulty in making such a principle responsible

for laying down the plan as well, c.g. in evolution.

We do

not need to seck far in the history of human thought. Ina large part of Greek philosophy pure mathematics and particularly geometry

was

always

looked

on with

profound

veneration as a reflection of the divine spirit—as in the

Pythagorean doctrine of harmonies or the Platonic doctrine of ideas. It is scarcely necessary to remind ourselves that for the majority of mankind, and often in particular for its intellectual leaders during the most fertile periods of its history, religion was

a living fact.

So when

we

use the

intentionally rather vague expression “extra-human spiritual

principle” we are only describing something that has been accepted as a matter of course throughout practically the whole of human history, in some concrete sense or other.

Thus there is not much difference in the metaphysical situation as between teleology and causal laws, although at first sight there appeared to be. The scientist will in the

first place ignore, and be right in ignoring, metaphysical questions, just as he has hitherto done so successfully in the case of causal laws. So we cannot see any objection to a teleologically oriented science. We shall now discuss a third vital phenomenon, the existence of consciousness. The term “‘consciousness” will

be used here to denote any psychic or intellectual activity,

from the simplest sense-perceptions and feelings and thought processes up to man’s consciousness of self. If there is one

thing of which our knowledge is certain, it is our own consciousness. Even if the outside world of the senses may,

as certain philosophers claim, be appearance, our own con-

THE

SCIENCE

OF

LIVING

THINGS

69

sciousness is certain. Moreover there is surely no doubt that animals possess consciousness (in the above sense) in varying degrees.

We can say at once that consciousness in any form

simply does not occur in the conceptual framework of physics and chemistry. The extreme materialistic trend in biology adopts the following standpoint. Stirrings of consciousness are phenomena accompanying physiological 1.6. physico-chemical processes in the brain and nervous system. They correspond uniquely to these material processes. The latter are however primary, and from this point of view

necessarily so, since it is physical laws that govern the course of events. Although there is of course no doubt that conscious processes and physiological processes are somehow connected, we can speedily dispose of the above proposition. In the first place it explains nothing at all. Merely to set up a parallelism between two completely different categories does not explain the existence of the second category. And secondly conscious and material processes proceed on entirely different lines. The latter obey quantitative and causal laws (in the sense of Chapter 1), the former are almost exclusively qualitative, and usually teleological. Our feeling of free will itself contradicts any proposition of the complete determination of consciousness by material processes. Thirdly, although it is true that bodily changes have psychic consequences, the reverse is also true. Psychology has long been aware that psychic disturbances can lead to bodily disturbances, and that strength of spirit can conquer bodily

weakness. Fourthly, the thesis is incapable of verification. It is not possible to observe physiological processes in the brain in detail (and this would certainly be necessary) without at the same time completely altering the psychological conditions. We shall come back to this point later. So it cannot be a question of material processes determining conscious processes; both subsist together, influencing each

70

MAN

AND

SCIENCE

other, somehow more or less closely interlocked. It then follows from this that physiological processes cannot be

governed by physics alone in the same way asin adead body.

The following comparison also provides an instructive illustration of what has been said. It has become fashionable to compare the brain and nervous system of the higher

animals and of man with the “electronic brain’, that mar-

vellous calculating machine that can perform computations

incomparably faster than any human being, that can play

chess and often beat a moderate player and always beat a beginner; or can do the bookkeeping for a big firm automatically and accurately.1 The name “electronic brain itself clearly shows that the intention is to reduce the brain to an electrical mechanism. The comparison is indeed highly instructive. There is no doubt that in the higher animals the nerve paths which regulate the automatic unconscious adaptation of muscular tensions to the proposed task and determine automatic reflex movements show an astonishing

resemblance to the circuits of the electronic brain and other machines. Some serious investigators have actually con-

structed machines that react to certain stimuli, for instance light, in a similar way to animals.

The comparison is however defective in several respects. In the first place there would be no electronic brain if it had not been invented by the brain of some human genius. But one cannot well compare

two things on a common

one of which is produced by the other.

basis,

In the second place

the nervous system consists not of electronic valves but of

living cells, of which not a single specimen has so far been

produced artificially.

Thirdly, the main point is lost in the

1 Recently the machine has, according to press reports, also been used to diagnose illness. The symptoms, contained on punched cards, are fed into the machine, which immediately gives the diagnosis. No doubt it will soon write the prescription as well. Has it come to this, that a section of humanity has succumbed to a mechanistic mania, as in former times it did to religious mania?

THE

comparison,

SCIENCE

namely

OF

LIVING

the question

THINGS

of how

71

the impulse

of

willing, that is, a purely psychic fact, sets this machinery

going.

The electronic brain is set in motion by punched

cards and by being connected to the electric supply.

But the

punched cards have in their turn been made by a human brain.

By itself, that is, without the aid of a human brain,

the electronic brain simply does not function. What the comparison does show us, if we

take it

seriously, is just about the opposite of what the constructors

of these anımated mechanisms to which we have referred

think they are showing. Ifthe nervous system is comparable with an electronic brain, then it has certainly not arisen by chance mutations. The chance would be about as likely as that a monkey playing with wires should accidentally “discover” the circuit diagram for the electronic brain.

And

it also follows that the nervous system clearly derives from a constructor or constructors who must have had at least the same amount of intelligence as the totality of the brain

workers (from Newton on) who have made the construction

of the electronic brain possible. And this must have taken place a few million years ago, since the origin of the higher

animal kingdom is according to palaeontological reckoning

at least as far back as that. We have here criticised the very widespread tendency in

biology which seeks to understand vital processes according to the patterns of physics and chemistry. Of course there

have

always

been

biologists,

and

there are some

even

at

present, who have been convinced of the contrary, and to

whom the existence of a plan is manifest in the vital process. It would take us much too far, and it is no part of our intention, to assess the value of all these latter trends in biology.

It is certain that they are not, or not yet, dominant, and so

far have not achieved a really deep understanding of vital

processes, comparable for instance with the understanding that physics has won for material processes.

72

MAN

AND

SCIENCE

Looking back over our argument, we might formulate

it roughly as follows.

Physical laws will certainly be neither

sufficient nor appropriate for a complete understanding of

typical vital processes.

Something is missing, just that

fundamental element that constitutes life.

This something,

of which so far we have scarcely any conception, will not be

“differential” like physics, i.c. will not in the first place be

operative from point to point; it will involve the wholeness

of the living being and its organs, an over-all plan, which gives direction not only to the growth of the individual being, but on a much grander scale to evolution. The

smallest space in which it can be effective is presumably that of the aggregates of macromolecules,

such as occur in the

chromosomes.t On a higher plane there must be scope in this something for consciousness to take a decisive place. So far science knows next to nothing about all this, and these vague indications must suffice. But one more question must be put and discussed in some detail. If physics and chemistry are not sufficient for understanding life, do physical laws cease to hold individually

whenever this living element occurs, or do they continue to

hold? Of course this question concerns the details of physical activity in the macromolecules. There is no sug-

gestion that a gross violation of physics could occur.

The

laws of gravitation, of statics and much else certainly hold in the living body.

We have repeatedly called attention to the fact that the existence ofa teleological principle does not necessarily mean a contradiction to the laws of physics. The chance initial conditions leave room for an “over-all plan”. It is perhaps

consciousness, in particular our feeling that we are free agents, that seems to some extent to conflict with physics and ! In his book (p. 67) Teilhard de Chardin goes so far as to ascribe to these macromolecules a rudimentary element of consciousness. We are not inclined to go so far; but an element of life, or at any rate something on which a life force can operate is undoubtedly present here.

THE

SCIENCE

OF LIVING THINGS

73

its inexorable course. But we shall in the main confine ourselves to the living body and disregard consciousness. Even then the problem is hard enough. Our question is extra-

ordinarily difficult to decide and perhaps it is impossible in principle. For we have seen that cell-division and heredity

take us into the realm of macromolecules, molecules that are very large but can still be called molecules, and are so irregularly built that a theoretical treatment of their reactions seems hopeless. Presumably it is just the same with other important vital

phenomena.

If we wanted to check the validity of physical

laws here, we would first have to determine the state of the

macromolecules accurately and in full detail by measurement.

This however requires, as we saw in Chapter 3,

powerful means (X-ray, etc.) which interfere with the object observed. Even ifit were possible to do all this in the laboratory, as it were in the test tube, with chromosome material in isolation, it is certainly not possible in the living

body. Bohr has used this fact to set up a very important hypothesis which attempts generally to clarify the relation be-

tween material-physical phenomena, and vital phenomena.

The hypothesis amounts to carrying over the principle of complementarity, which plays such a central role in quantum mechanics. Bohr assumes that material and vital processes are mutually complementary like position and velocity in quantum mechanics, that is, that accurate knowledge and

determination of material processes and vital processes are mutually exclusive. So if we regard the living body, the

physical processes in the all-important macromolecules remain “to a certain extent’ indeterminate. The “certain extent” probably refers only to the details of the molecular process, a knowledge of which would however be necessary

to fix the physical course of events uniquely. If on the other hand we try to follow the physical process in detail, we can F

74

MAN

AND

SCIENCE

only do so if we are prepared to accept a violent act of interference. We already know for instance that irradiation of the sex cells with X-rays produces mutations, thus decisively disturbing vital processes. Ifthe physical analysis were to be carried so far (if this is possible at all) as to disclose the physical phenomena in the chromosomes completely, it is quite likely that the chromosomes would be killed in the process. The same must hold with even greater force for the key cells of the nervous system. It is difficult to imagine that one could investigate closely the physical processes in vitally important brain cells without destroying the whole organism. Thus Bohr’s hypothesis does not mean that there is any direct violation of physical laws in the living body; but it does mean that these laws cannot be verified as long as the body is alive, and alive without interference.

An attempt

to verify the validity of physics would—if possible at all— yield a positive result—but we would then have a corpse on our hands. If we want to investigate the actually living, we must renounce an over-detailed description of molecular processes. It is as if the macromolecules in the living state are no longer described in full detail physically. Something comes in instead which extends over the whole organism—the typical vital factor. It is just because physico-chemical processes are not fixed with complete precision that room is made for the “vital something” that governs the vital functions with their wholeness and their development in conformity with the plan. Of course the position of the limit at which our renunciation of “detailed physical description” would have to begin is still quite uncertain. At present we are presumably still far from this limit. We must call attention to an obvious fallacy. In Chapter 3 we saw that the physics of atoms and molecules is essen-

tially indeterminate.

One might suppose that the latitude

THE

SCIENCE

OF

LIVING

THINGS

75

this appears to leave could be related somehow to human free

will, or be taken up by something else, which might perhaps

correspond to life. This is however impossible. It can be shown (we cannot develop this here) that this latitude cannot be taken up in any way without giving rise to internal

contradictions. Furthermore, the laws of quantum mechanics are indeterminate only if measurements are made or if there are external influences such as X-rays. Anisolated quantum-

mechanical system behaves deterministically, (though not in space and time). Morever, a living body would then not be essentially distinct from a dead body.

hypothesis,

If we accept Bohr’s

the implication is that in the living body

the

molecules are not completely described even in the sense of quantum

mechanics.

So far Bohr’s idea is nothing

more

hypothesis, but it has many likely features.

than a working

Its chief impor-

tance is that it provides scope for a future science of life which is not tied to the idea, so crippling when applied to anything living, of the inexorable course of events.

It is of course obvious that the problems treated in this

chapter are far more crucial for ourselves as human beings than physics.

Even if we can afford to maintain a certain

reserve or detachment in regard to the exact sciences (that this is not actually possible we have seen in the first three chapters) here in biology we are ourselves the object of investigation. A science which adopts the standpoint that vital processes are defined in a physically determinate way and persists in it, can only lead to a complete loss of reverence for life.

The consequences for mankind itself would be

catastrophic.

But we hope that we have indicated reasons

enough to show that this standpoint is false.

Chapter

5

The Cosmos HERE is scarcely any field of science which has played

such a revolutionary and controversial role historically as the problem of the structure of the universe. Originally it was the problem in the narrow sense of the

structure of the planetary system.

It is common knowledge

that the transition to the Copernican system with the sun at the centre made possible the discovery of Kepler's three

laws, which in their turn were the basis of

Newton's work,

so that it was cosmology that led up to the scientific revolution of the early seventeenth century. For our present purpose, however, this is not what matters.

It was a revolution

not so much against certain fixed scientific views, but against

the theological universe of the middle ages. The characters in the drama were, of course, hardly conscious of their

revolutionary role, not even, it seems, the protagonist of the

modern scientific view of the world, Galileo. The middle ages adhered to the view that the earth is the centre of the world, although there had previously been Greek philosophers, e.g. Aristarchus, who put the sun at the centre.

The

modern physical conception, 1.6. the “Copernican system” had thus been familiar for a long time.

There was however a

good reason for keeping to the geocentric system; the reason was a theological one. Man was the highest living being still tied to a body. “Above” him were ranged the incorporeal hierarchies of the angels, and “above” these again, God, the creator.

As the highest terrestrial being man

1 A very interesting picture of this highly important epoch of history is

to be found in A. Koestler’s book The Sleepwalkers. 76

THE

COSMOS

77

could claim the especial care of these hierarchies. Man was also the “lowest” being endowed with a soul. Conse-

quently, man’s habitation must also lie “below” everything else, i.e. at the centre of the universe.

The words “above”

and “below” are put in inverted commas, because they are

used in a double sense, firstly in the sense of superiority or inferiority in intelligence or otherwise, and secondly in a purely geometric and physical sense. The distinction between intellectual and physical qualities seems to be of quite recent date. The mediaeval universe, that is, the geocentric

system with its hierarchical order, and to a large extent the classical universe,

as in Plato’s

Timaeus,

was

thus both

a

physical and a metaphysical construct, with man at its centre.

And this was quite essential for theology. No wonder that the mere idea of shifting the centre to the sun caused a great stir among scientists and theologians. The only comparable repetition of this drama occurred in connection with Darwin's theory of evolution. Kepler had tried to bolster up the idea theologically. The sun was the seat of God, and hence was the centre, from which all actions emanated,

spiritual as well as physical—again no clear distinction is made.

But he was unable to prevent the initiation of a process

fraught with grave consequences, the process which deposed

man from the place he occupied as the highest embodied living being, and in which he was unique. And this was bound

to have other more far-reaching theological consequences.

If the earth was only one among six planets, and was thus “raised up into heaven”, the hierarchical order was at once

destroyed;!

likewise man’s central role was shattered.

Who

1 The phrase is from John Donne’s Ignatius his Conclave, published in 1611. Ignatius and Copernicus are contesting for the place of honour in Hell. Ignatius says to Copernicus, ‘Hath your raising up of the earth into heaven brought men to that confidence, that they build new towers or threaten God againe? Or do they out of this motion of the earth conclude that there is no Hell, or deny the punishment of sin?” We recognise the fear of disturbing the hierarchical order. (The passage 1s quoted from Koestler’s book mentioned above.)

78

MAN

AND

SCIENCE

could be sure that the other planets are not also inhabited? And ifthe universe does not revolve in a physical sense about

the earth, why then should it turn in a spiritual sense about

man?

As wc have already said it was not easy to discrimi-

nate at the beginning

of the seventeenth century.

not until later that it was known

It was

that atmospheric con-

ditions on the other planets arc such that life in any way

resembling terrestrial life can hardly exist on them, and that there are certainly no human beings like ourselves on

them. As astronomy developed the process continued.

The

celestial sphere of the fixed stars unfolded itself as a system of countless stars extended over vast spaces, the galactic system, each one of which more or less resembles our sun, and a very large number of which are certainly surrounded

by planets.

And this is only our particular “little” galaxy.

At much greater distances still there are enormous numbers

of spiral nebulae, each of the type and dimensions of the galactic

system,

with

a similarly

enormous

number

of

individual suns. The whole extends over inconceivably great distances. Here the conclusion was really inescapable that in these countless solar systems there are planets with

conditions similar to those on earth, on which life could

develop and on which evolution has advanced to the stage of man or perhaps even further.

It would be an unlikely

chance if just our earth should be the only one privileged

to afford shelter to man. At this stage the gulf which was gradually opening between science and religion was bound, inevitably, to

become almost unbridgeable.

Expressing it briefly if at the

same time crudely, we might say that if a Creator of all these worlds and spaces exists, then he has removed himself to such a distance that terrestrial man can hardly claim or expect his

special solicitude. But a creator who cares specially for our earth and our solar system would no longer be a universal

THE

COSMOS

79

creator. Of course this conclusion was rarely drawn consciously by the investigators concerned; but the divorce of religion from science followed from it automatically and almost of necessity. With Copernicus and the scientific revolution which was

inaugurated shortly after him, there began that divorce between science and theology which is practically complete

at the present time. There were of course other contributory factors. Controversy in the nineteenth century about

Darwin’s theory of evolution, which puts the origin of life inconceivably far back in time, namely some 100 to 1000 million years ago, gave a further impulse in the same

direction.

The mere discovery of causal laws of nature was

partly responsible for this development, although the first discoverers, including Newton, never saw any contradiction

between theology and the existence of laws of nature, nor do many modern investigators. It was only through the separation of religion and science

that it became possible to obtain a clear view of the purely physical realities of the external world unencumbered by metaphysics; indeed the separation was indispensable for

this purpose. At the end of the sixteenth century this clear view had not yet been achieved. This led to the conscious

elimination from science of practically all metaphysical elements. Desirable though this liberation from metaphysics was in one respect, it had unfortunate results, in that

henceforth physics was regarded as the sole reality.

appeared to contradict all previous conceptions universe in which the emphasis was metaphysical.

Physics

of the These

conceptions were thereby discredited, and in general the

cosmos and the phenomena of nature were robbed of all

spirituality.

Theology was deprived of a corner-stone,

vitally important at the time, and was forced into a defensive position. Ultimately man was reduced to an insignificant being, and the materialistic-mechanistic trend received the

80

MAN

AND

SCIENCE

impetus we have already described.t Logical and compelling though the whole argument appears, there is latent in it one conclusion that we will recognise as doubtful, not to say fallacious. Before coming to this however we shall elaborate the astronomical picture of the universe in rather greater detail, with a few numerical data.

A comparatively easily pictured measure for astrono-

mical distances is the light-year, that is, the distance light travels in a year. Since the velocity of light is about 300,000 km per second, and there are about 30 million seconds ina year, the light-year is about 101°= τὸ billion km. The distance of the sun from us is only 8 light-minutes. The nearest fixed star is 43 light-years away. The galaxy is a 1 The fact that the discovery of causal laws led, in spite of their obvious metaphysical implications, to the agnostic philosophy of the nineteenth century must be understood in its historical setting. In the first place these laws contradicted the fossilised church dogma of the time. Exaggerating and generalising a little, we could have argued roughly as follows: “Science has proved that the world was not created 6000 years ago. Hence all religion is false’. But the root of the matter lies deeper. With the coming of the scientific revolution of the early seventeenth century a few individuals at first and later large numbers attained what one might almost call a new faculty, that of rational and mathematical treatment of nature. This was diametrically opposed to the mode of thought of mediaeval man, a mode of thought condemned to gradual extinction under the impact of the new-born science. In the full consciousness of this newly acquired power, the power of rational thought applied to natural processes, it is readily understandable that the metaphysical aspect of the newly discovered regularities should be overlooked or neglected. The great investigators on whose shoulders the philosophical materialists stood were by no means superficial thinkers; they were profoundly convinced of their philosophy. In this materialism, which is so to speak at the opposite pole to mediaeval philosophy, we must recognise a certain ““historical necessity’’. Only a radical turning away from the middle ages could make knowledge of the physical external world possible. Of course it is unthinkable (and undesirable) that we should return to the modes of thought of the middle ages. Our path can lead only by way of and beyond science. But the time is indeed ripe for us to begin to be aware of the metaphysical questions concealed behind the laws of nature, even if in the meantime we cannot answer them, or do not, in our capacity

as scientists, intend to answer them. But at the same time we ought to stop offering as a “world picture’ that meaningless quantitative and deterministic machine that is nowadays represented as being the result of scientific research on nature.

THE

COSMOS

81

flat spiral with a diameter of some 10,000 light-years.

It

contains many thousand millions of stars, each more or less like our sun. Outside the galaxy there is practically a void

(at any rate as compared with the not exactly densely populated galaxy) extending to the nearest spiral nebulae. These

are about one million light-years distant. Each spiral nebula is more or less comparable in structure and size with the

galaxy.

At distances of the same order again there are in-

numerable further spiral nebulae.

The most remote that

can be observed today with the biggest telescope (on Mount Palomar) are at a distance of many thousand million lightyears. So we 866 the spiral nebulae not as they are now— that is never possible—but as they were a million or a thousand million years ago.

nebulae that have runs into millions, in the part of the certainly exceeds

To date, the number of spiral

been recorded on photographic plates but the number that must be contained universe now accessible to observation a thousand million. The reader can

work out for himself the number of solar systems in the universe.

In addition there is a further group of most important

discoveries.

It is not long ago that the space of the universe

was regarded as infinitely great in spite of all the conceptual and physical difficulties this assumption raised. For a wall bounding the universe is barely possible. But Einstein’s

general theory of relativity opened up the possibility of conceiving of unbounded yet finite space. This is possible through the idea of space curvature. We can readily imagine a curved two-dimensional surface, and it corresponds to our every-day experience. A closed surface has no

boundary, yet it is not infinitely large. The simplest example is the surface of a sphere. If we move on the surface of a sphere we never come to a boundary, yet the surface of the sphere is finite. A curved three-dimensional

space is much more difficult to imagine, because there is no

82

MAN

AND

SCIENCE

fourth dimension for the space to be curved in.

Curved

space is nevertheless perfectly conceivable mathematically

and can be described geometrically. The fourth dimension is not necessary at all. The curvature properties can be determined by purely geometrical measurements. The curvature of the earth’s surface can also be determined without using the third dimension. To do this we have only to

measure meridians and circles of latitude.

It is practically

certain that the space of the universe is in reality curved.

It

is possible that on the grand scale it is a closed space analogous to the surface of a sphere, so that while there is no

boundary anywhere its total volume is finite. If then we were to go on and on in the same direction we would

ultimately come back to our starting point, just as a traveller

continually going due east along the earth’s equator would return to his starting point.

Whether this is true for the

space of the universe has not yet been proved, but the assumption is so plausible that it is accepted nowadays by many workers. Now comes a further discovery. We can determine, by an exact

analysis

of the light

emitted,

whether

a light-

source is moving towards us or away from us. If the lightsource is moving away from us, it becomes redder, if towards us bluer. It is even possible to measure the velocity in the line of sight with considerable accuracy merely by investigating the colour change of the emitted light. Observations of distant spiral nebulae have disclosed the remarkable fact that these spiral nebulae are all moving

away from us, some of them with very great velocities.

Still more remarkable is the fact that the velocity is greater

the more distant the spiral nebula.

The radial velocity is

approximately proportional to the distance. The most distant spiral nebulae that can be observed nowadays have velocities approaching one half that of light. If we accept

the above picture of a spherical universe, we can understand

THE

this fact as follows.

COSMOS

83

Instead of considering curved three-

dimensional space, which is difficult to picture, we again consider the two-dimensional analogue, the surface of the

sphere.

Think for instance of a rubber balloon.

On its

surface we mark points more or less uniformly distributed,

corresponding to the individual spiral nebulae. The distance apart of two points is of course to be reckoned along the surface in the same way as we measure the distance between two towns on the earth's surface. We now imagine the

balloon to be slowly inflated so that its radius grows at a uniform rate.

The distance apart of the points on the sphere

will then also increase.

If we select a particular point (our

own galaxy) and regard all the other points from it, then clearly all these other points will move away from the point of observation. A simple consideration shows that the speed with which the other points move away is greater the greater the distance from the point from which they are observed, always measured along the surface of the sphere.

The radial motion of the spiral nebulae thus becomes comprehensible if we assume a spherical world, having of course three dimensions, whose “‘radius’”’ is not constant but increases uniformly.

We need not keep to this picture in detail. But we can draw two conclusions with fair certainty. If the empirical

law of radial velocities proportional to the distance con-

tinues to hold at even greater distances, a limit will soon be reached at which the spiral nebulae are moving with the

velocity of light. But such nebulae cannot exist—if they did they would be invisible in principle. The theory of relativity just

does

velocity of light.

not

allow

bodies

to move

with

the

Moreover the physicist knows that if a

light-source were to move with the velocity of light it would no longer radiate visible light. So no actions what-

ever can reach us from such spiral nebulae. Thus there is, in principle, a limit to the observable part of the universe; as

84

MAN

AND

SCIENCE

we have alrcady got up to about half the speed of light the limit is likely to be not much more than twice as far away as the most distant spiral nebulae known today. Presumably this limit coincides approximately with half the “circumference’ of the universe, if we take the universe as the three-

dimensional analogue of the surface of the sphere. At any rate there is a definite limit to the distances possible. According to present estimates this limit is some ten thousand million light-years distant. Secondly let us follow the constantly expanding universe backwards in time;

in retrospect the universe keeps getting

smaller. A time comes in the past when the radius of the universe was zero, so that there was as yet no space. We can estimate this time from the present velocity of expansion; it lies a few thousand million years in the past. Of course, this is not to be taken quite literally; but we can say that we are certainly not justified in extending the time scale arbitrarily far back. At the “instant” in question conditions would have been so different that we could not possibly use the terms time and space at all. (Weare speaking throughout in the sense of the mathematical concepts of space and time.

For the “subjective time’ of human beings,

see below.) We are thus justified in speaking of the beginning of the world in time. “Before” this none of our concepts have any meaning at all. There is simply no such thing as a “before” in this sense. It is remarkable that the age of the universe determined in this way agrees very roughly with the age assigned by astronomers to our solar system. Let us now analyse how we have arrived at this picture, the grandeur of which leaves nothing to be desired. It is evident that these insights are based solely on the action of light coming to us from these distant worlds. More recently radio waves, which are also cmitted by and reach us from

THE

COSMOS

85

heavenly bodies, have been included, but this makes no real difference. We analyse these optical effects with our physical instruments on the earth, by well-tried physical methods, and draw conclusions about the distant light sources which have emitted the radiation. In so doing, we make one assumption. We assume that the same physical laws hold throughout the whole universe as on our earth, or let us say in our solar system. This assumption has been found to be well justified. Individual observations are consistent, and at no point has any conflict arisen with the laws of physics. The observations yield a unified physical picture of the universe. Nevertheless it remains an assumption.

We

cannot verify

the validity of physics in the spiral nebulae or in the galaxy

directly. We can investigate the light from a moving lightsource on the earth and derive the velocity from the colour change caused by the motion, just as we do for the spiral

nebulae.

But we can also observe and measure the motion

of the light-source directly, and thus verify the physical law relating colour change and velocity. This is not possible in the universe at large. One might think of space travel in this connection. If we should succeed in penetrating into interplanetary space, with human beings carrying out experi-

ments, we would indeed be able to verify the validity of

physics within the solar system.

But the space traveller can

move with the velocity of light at the most, and that only in

theory.

It is not very likely that he would reach even the

nearest fixed star.

At the velocity of light it would take him

over four years, and he will certainly not be able to reach the

nearest spiral nebula, years. He does not physics in world space isa refutation. When

for which he would need a million live so long. So a verification of is not to be thought of, nor of course put in this absolute form the question

whether physics is or is not valid throughout the universe does not, in principle, admit an answer. The fact that it is possible to fit all astronomical observa-

86

MAN

AND

SCIENCE

tions consistently into the scheme of terrestrial physical laws

is generally regarded as a “proof” of the validity of physics

throughout the universe. The scientist often has to be satisfied with proofs of this kind, and he can do so with a clear conscience. The assumption that physics holds throughout the universe is, from the point of view of physical astronomy, the only reasonable one, and presumably the only one possible. This does not however alter the fact that at this point a transference of terrestrial conditions to the universe is involved. The astronomical picture of the universe with its immense

distances and intervals of time,

never accessible to

man, thus arises by extrapolation of geometry and physics

to the universe.

It is a picture which is obtained by mental

processes on the part of the investigator, but of which man

can have no other experience. The extrapolation is fully justified and we can take it that it will never conflict with astronomical and physical observations. This does not mean, however,

absolute truth.

that the picture is the sole, exclusive and

As soon as we leave the realm of physics and

astronomy, we should proceed with caution in regard to its

truth-content, and bear in mind the mental process by which it was obtained. We should not for instance, use it uncritically to draw far-reaching theological conclusions from it. Theology orginates in a region of human experience completely different from the mental processes and observa-

tions of the astronomer.

At any rate the justification for

drawing theological conclusions, like those mentioned at the

beginning of this chapter, from the astronomical world-

picture seems very doubtful. We shall see immediately that there is a difficulty about such conclusions.

We had propounded the question as to life on other heavenly bodies outside the solar system. By life we of

course mean living beings more or less comparable with terrestrial beings. Such beings emit neither light nor any

THE

COSMOS

87

other rays that could reach us here.!

As we cannot our-

selves penetrate into interstellar space the question is simply

unanswerable, since science itself does not allow us to reach these heavenly bodies during our lifetime and obtain an answer to our question. A question that simply cannot be answered is not a genuine scientific question;

it is not much

more than a pseudo-question. The history of human thought is full of pseudo-questions. Infinite ingenuity and considerable passion has been expended on their discussion. A classic example is, how many angels can stand on the point of a needle?, or, can God create a triangular circle? Often however pseudo-questions are much more difficult to recognise as such, and sometimes

progress consists just in

uncovering the spurious nature of a problem. Modern examples would be: what is the colour of an atom?, or, in what orbit does the electron in an atom move? (cf. chapter

3). It takes a knowledge of the whole of quantum mechanics to recognise that this is a pseudo-question.

Our question as to life on the fixed stars is perhaps not quite as meaningless as the first two scholastic examples, but

not much more meaningful than the two modern ones.

It

can therefore be ignored for our philosophy as a whole, and has to be ignored if we are not to move in entirely wrong directions in other fields—philosophical, religious, etc. Terrestrial life, with the possible inclusion of life on neighbour-

ing planets, which is not very likely, is thus for practical purposes unique, and above all, terrestrial man is unique.

In this sense we may confidently regard the earth as the

centre, not of the universe, but of life. And regarded from this standpoint the appearance of the universe is somewhat different as compared with its appearance to the astronomer

1 The idea has been put forward that “men” on distant heavenly bodies could have sent out radio signals (in a decipherable language?) in order to make contact with us. As long as no such signals have been detected and unambiguously deciphered, the author is not concerned about the point of view adopted above, and he recommends this course to the reader.

88

MAN

AND

SCIENCE

making physical observations. It is after all on the earth that human life is staged, and man is the centre of all mental

activity, religious and scientific.

The whole grand astro-

nomical picture of the universe, too, originated in terrestrial

and human mental activity. All the spaces of the cosmos are irrelevant for our life, and are of purely scientific interest. As we have seen, space travel does not affect this.

is no question of changing

For there

our habitat even within our

planetary system, although some newspaper articles sound as

if we could in the near future “emigrate” without further ado to another planet.

What value are we now to put upon the astronomical picture of the universe? We got as far as saying that it 1s a picture obtained by extrapolation of physics to observations of the system of the fixed stars. Naturally this picture is subject to the same limitations as physics itself, that is, it represents the causal and quantitative aspect of the universe.

The extrapolation is also in respect of the distances and of the enormous time intervals extended into the past; these too are extrapolations. Our concept of distance as well as our concept of time derive from terrestrial conditions. We have a feeling of what a year or a thousand years of human history are, and what is meant by a few thousand kilometres

of distance.

Not much

more is needed to extend these

dimensions to conditions in the solar system.

But we have

no feeling for what millions of years mean, or distances of

millions of light-years. These mean little more to us than unattainable. This remote past or these vast distances can

never be, nor can ever have been experienced or witnessed

by man.

They are mathematical and physical extrapola-

tions, based on ordinary well-known terrestrial data, to vastly different dimensions. By means of these extrapolations we project our physics into the universe. In this way we

obtain what we

may

call, using

our

previous

image

once again, the physical aspect of the universe, the projec-

THE

COSMOS

89

tion, so to speak, of the universe on to the physical plane. It is in this sense, and in this sense only, that it is valid. This is a brief statement of what the astronomical picture represents, and at the same time it indicates its limitations.

It is

not impossible that there could also be other aspects of the

universe, perhaps of a more metaphysical character. At all events we ought to guard against accepting the astronomical

picture without question as true coin in the metaphysical

sense as well. The conflict between science and theology, which at one time was so violent, and as a result of which two of the most important mental activities of man now stand apparently opposed and mutually contradictory—this controversy was, as so often happens, mainly a controversy about unwarranted

generalisations.

The theologians did not see that physics is

something different from metaphysics and the astronomers did not see that metaphysics

physics.

is something

different from

When we were discussing the exact sciences (Chapters 1

and 2) and found that they represent the causal and quantitative aspect of the external world, it was already clear what

aspects were not contained in this physical projected image.

These aspects included all the qualities, everything that is not measurable, perhaps much else as well. These qualities

were however the most important part of our direct appre-

hension of the external world;

directly in our consciousness of it.

exists by way

they were what

exists

Of the universe nothing

of direct sense-apprehension

save the bare

aspect of the starry heavens. If we ask whether there are other aspects than the physical aspects of the universe we can

no longer confine

ourselves

to direct sense apprehension.

The question is much deeper and more difficult and probably purely metaphysical. Any answer must be largely specula-

tive.

If we do not simply give a direct negative, it is because

firstly, more than two and a half millennia, possibly more, G

90

MAN

AND

SCIENCE

of human history attest the contrary, and secondly because the limitations of physics are already well-known and obvious to us. The limitation of astronomy is still more farreaching because it involves the extrapolations we have mentioned. We could leave the question unanswered. A conclusive answer is in any case impossible. In view of the historically close connection or even identity of astronomy and metaphysics and the consequences of their divorce, a few speculative indications would seem to be permissible. The mediaeval and to a large extent the classical universe was, as we have said, a unity of physics and metaphysics. It is Open to question whether the main emphasis was not indeed on the latter. We see the erroneous! physical side more clearly because we are nowadays mainly interested in it, and it is only since the scientific revolution that we have been able to see physics unencumbered by metaphysics. It is even possible that we sometimes read physics into the old conceptions, where they were meant to be taken metaphysically.® So itis conceivable that just this metaphysical part contains a certain measure of truth. We would at any rate

have no right to deny this on the basis of our science, now

that we have recognised the limitations to which the physical picture is subject. And after all those who formulated the metaphysical universe possessed intellects of no mean order. 1 Actually

the Ptolemaic

planetary

system

which

held

the field from

antiquity up to the time of Copernicus can hardly be described as wholly erroneous. If we choose the earth as our point of observation (which 1s not wrong, but merely inappropriate) the planetary motions are very complicated. The Ptolemaic system describes them by elaborate superimposed circular motions, but allows the planetary motions to be calculated in advance with considerable accuracy. It thus represents a useful approximation to the actual orbits (as scen from the earth). In thinking of the system of Copernicus and Kepler as the “correct” one, as we do today, we do so for reasons of simplicity and general clarity. It is only in this way that we can reduce the motion of the planets to the fundamental laws of mechanics, and so recognise the connection between mechanics and astronomy. 2 The low regard in which observation by the senses as a means of knowledge of the world was held strongly suggests this conjecture.

THE

To

be

more

concrete,

COSMOS

ΟἹ

let us consider

as an

example

Pythagoras and his doctrine of the harmony of the spheres.

This doctrine has fascinated thinkers throughout two millennia, up to and including Kepler. It is scarcely open to doubt that Pythagoras is one of the greatest men humanity

has produced.

How the idea of harmony of the spheres

arose is not known with certainty, for the doctrine of the Pythagoreans was for long a secret. Ancient tradition

asserts that he was able to apprehend the harmonies in some

supra-sensuous

way.

Mere

to

of terrestrial

optical

observation

could

scarcely suggest the idea. It does not sound very likely either that it was a question of an imaginative transference the

cosmos

harmonies

relationships associated with them.

and

the

integral

The universe of the

Pythagorean and Platonic schools of Greek philosophy was

animistic throughout and “endowed with spirit”. The same is true for other ancient world philosophies, e.g. Indian philosophy, and views of this kind date back to long

before Pythagoras’ time.

Perhaps the biblical story of the

creation or the detailed Indian account of the evolution of

the world can be regarded as pictorial representations of metaphysical facts and events also having reference to the

cosmos.

Seen against this background the harmony of the

spheres appears rather as a detail in an over-all picture of the

cosmos that is markedly metaphysical. Presumably the origin of such views is in mysticism, which modern man can hardly understand, and is probably based on practical spiritual

knowledge and experiences, of which at least isolated individuals

of the ancient

world

were

capable.

There

are

recurrent reports throughout the whole of human history

of supra-sensuous or mystic experiences, and much of this is undoubtedly genuine. The integrity of many outstanding persons is to some extent a guarantee.

legend or imposture.

Much of it is certainly

Modern science does not warrant our

simply rejecting all this or degrading it to the level of

02

MAN

AND

SCIENCE

hysteria, unless we are swayed by intense prejudice or

arrogance. What the facts are in regard to Pythagoras and his apprehension of the harmonics we cannot now tell with certainty.

But assuming that there is a grain of truth in them, it would

point to a completely different aspect of the universe that cannot in principle be contained in the physical aspect.! The

same applics to the whole spirit-inhabited universe of classical and oriental universal philosophics. We find metaphysical aspects of the cosmos hinted at everywhere, aspects in which as yet no connection is recognisable with the

picture of the world given by physics and astronomy, but

all of which it is nevertheless hardly possible summarily to ignore. Weare concerned only to establish that the universe, like the world in general, can have aspects of which the physical picture reveals nothing, aspects which indeed on a super-

ficial view appear to conflict with the physical picture. We should have learnt by this time that what at first appears as contradictory is. not necessarily contradictory. Within physics, quantum

mechanics

is a good

example

of how

a

contradiction can be resolved by the formation of higher concepts.

There would be no logical incompatibility between the

physical and astronomical

aspect and

such

metaphysical

aspects for the reason that they are based on experiences of different kinds, and so lie on different planes. Apparent contradictions between two such aspects do not necessarily

imply that one of them is false. It might be that we merely lack the concepts that would enable us to see that both are justified as parts of a higher unity. We

are scarcely able at present to determine

the real

1 ‘Whether Kepler was on quite the right lines in seeking the harmonies, which are presumably of a purely spiritual nature, in the physical relations of the planetary orbits is again another question.

THE

COSMOS

93

truth-content of the ancient metaphysical conceptions of the universe. We shall not declare for any one of them. But

one thing must be said emphatically, and that is that we

must maintain the freedom from prejudice that befits the

scientist, even in regard to matters that do not enter into the

scientific philosophy of Galileo and his successors.

Conclusion ET us try to summarisc what we have said and as far as

possible obtain from it a unified picture.

Our route

has taken us through several of the most important fields of science. We began with the exact sciences, in

particular physics.

We saw that they are governed by two

principles, causality and the quantitative principle. In these sciences we look only for laws that can be formulated causally, that is, laws in which some cause, e.g. the data at an instant of time, determines the subsequent course of events; and we seck only those laws which refer to quantitative phenomena and can be formulated quantitatively. Thus from the very start science imposes a limitation on itself, and

its success

undoubtedly

depends

on

this limitation. We

have frequently considered, as a counter-example to causality, regularities whose significance lies in an over-all plan or

in a purpose to be achieved (teleology). from scientific consideration,

although

These are excluded causality and

ology are not necessarily contradictory.

tele-

All qualitative

phenomena are likewise excluded, colour, odour, form and

much besides. We have also seen that these qualities cannot

simply be ascribed to our inner life.

There is probably no

sharp dividing line, free from any arbitrariness, between an external world (which according to physics would be purely quantitative) and our inner life. When we are occupied

with physics we fix the boundary arbitrarily in such a way that all these qualities lie on the far side of the boundary of physics. The self-imposed limitation thus has the effect of

excluding whole domains of phenomena.

We expressed

this by saying that physics describes the causal and quantita-

tive aspects of the world, a sort of image projected on the 94

CONCLUSION

95

causal and quantitative plane, but certainly not a complete

image.

In astronomy (to keep to the exact sciences) the limitation

extends still further, at least as regards the system of the fixed stars. Here the universal validity of the laws of physics in space is assumed, an assumption which can neither be verified nor refuted. In the astronomical picture of the universe we have a picture that is the result of extrapolation

of physics into world-space.

It represents the physical aspect

of the universe, and this does not exclude the possibility that there may be other quite different aspects, having, it may be,

a more metaphysical character (cf. Chapter 5).

The principle of causality leads, in its strictest form, to a strict determinism. This means that the whole of the future

follows with mathematical precision from the (sufficiently detailed) data at one instant of time. The laws of classical

physics are of this kind, i.e. the physics of large bodies consisting of many atoms and molecules, (including a particle of dust). But in the world of atoms this principle in

the strict form quoted is violated.

As soon as observations

are made on a single atom strict determinism no longer holds, and statements about probability take the place of exact predictions. Moreover observer and object can no longer be sharply separated, since every observation affects

the object in an unpredictable manner. The

principle

of causality

as well

as the

quantitative

principle led to an estrangement of the scientific worldpicture from life, and above all, from human life. Man thinks causally and quantitatively only when he is thinking

scientifically, (and quantitatively also in business affairs). Not

so

in

normal

human

life,

which

is

dominated

rather by the setting of aims, on a large or small scale, and by qualitative sensations. The scientific world-picture no longer bears much relation to human life. Should we then be surprised that many of the applications of science have

96

MAN

AND

SCIENCE

proved definitely inimical to life?

But it was scarcely to be

expected that some of these applications would turn out to

be quite as evil as they have done. It is precisely this fact, however, that shows the extent of the estrangement between science and life.

The limitations we have mentioned manifest themselves

even more decisively in biology. If we apply the same principles as we use in physics to the living body, we will, as we have seen, be unable to understand just the most typical

vital phenomena. the form resistance

These include for instance morphology,

and size of the living body and its organs, its to decay, also evolution of lower to higher

organisms, and of course the existence of consciousness in the

higher animals and in man.

Quite different principles will

have to be used if anything of this is to be understood, principles in which the wholeness of the living organism and of its organs in respect of form and function is essential;

principles which involve something essentially new, the

typical vital element, in which the over-all plan is decisive in the architecture of the living organism as well as in its evolution. We came to the conclusion that in biology

teleology must play an important part in supplementing

causality, which is not to say that both principles, teleology and causality together,

will suffice for

standing of the living body.

a complete

under-

At any rate the exclusive appli-

cation of the principle of causality in biology, in particular the exclusive use of physico-chemical laws in living bodies

will give us only a very limited excerpt from the science of

life, an excerpt more suited to describe the dead body than actual living matter, which bypasses just the most typical

vital phenomena.

Biology will undoubtedly make further

progress along the present lines which stress the causal quantitative or the physical and chemical aspects, and certainly achieve even greater success than hitherto. haps some day it will even be possible to synthesise

and will Perthe

CONCLUSION

97

DNA molecule and proteins. Perhaps indeed these substances will exhibit properties with a remote resemblance to living matter. If a prophecy expressing our own feeling

may be permitted, the living things so produced would be caricatures of real living things, homunculus-creatures in-

spiring only revulsion but devoid of all positive character.

Reviewing what has been said we must admit that con-

temporary science presents an aspect of the world so restricted that it appears small compared with the problems that have not so much as been touched on, all the magnificent

achievements of science notwithstanding.

This aspect is

concerned only with the material side of the world, which

is just the side that concerns man less, save for its technical applications.

In particular

we

sce that little justification

remains for seeing the world as a causally running mechanism. stition.

Belief in a mechanistic universe is a modern superAs probably happens in most cases of superstition,

the belief is based on a more or less extensive series of correct

facts, facts which are subsequently warrant, and finally so distorted

generalised without that they become

grotesque. A mechanistic living creature presents the grotesque picture of a robot such as is frequently portrayed in comic papers nowadays. The witch superstition has cost in-

numerable

innocent

women

their

lives,

in

the

cruellest

fashion. The mechanistic superstition is more dangerous. It leads to a general spiritual and moral drying-up which can easily lead to physical destruction. When once we have

got to the stage of seeing in man merely a complex machine,

what does it matter if we destroy him? Perhaps some readers will think that in taking this stand

in opposition to the mechanical conception of the world we

1 Even the belief in witches seems to have some factual basis. According to a recent report a chemist is said to have made up the ointment with which mediaeval witches are supposed to have anointed themselves, and tried it out on himself. He passed into a trance state which was alleged to be not unlike the well-known witches’ ride.

98

MAN

AND

SCIENCE

are hammering at an open door. Philosophical materialism reached its zenith about the end of the nineteenth century

and it is probably true that this philosophy is no longer very widely held. But after all it is science more than anything

else that calls the tune nowadays.!

Within science itself

however there are as yet only few indications that any trend

other than the causal and quantitative is being followed—

rather the reverse. Moreover the limitations inherent in this trend have rarely been consciously realised, and even if we

do not profess a materialist philosophy this philosophy is

being applied increasingly in scientific practice. Nowadays our private philosophy and our science are often two different things. There is no bridge connecting science with our life as human beings, except through material and technical applications, whose character we have already

described.

It is generally said that science, which is the search for truth, is neither moral nor immoral, but only that those who put its applications into practice are faced with ethical

decisions.

In view of our results we can agree with this view

only with one proviso. The search for truth can surely not be immoral. But we have seen that modern research is conducted mainly along channels leading further and further away from all that is human. And then this science puts

forward a claim to total validity, setting itself up to be the

whole and only truth. But a partial truth that claims to be the whole truth may very well be immoral. Is this perhaps the reason for the demonic character of science mentioned in the introduction? At all events this claim to total validity

is in danger of destroying all reverence for life. We still possess a large capital of humanism which stands between us and this danger. It is derived chiefly from the

past.

For most people of course human and ethical values

1 The reader who has read thus far will scarcely attribute this assertion to scientific arrogance on the author’s part.

CONCLUSION still have significance.

99

But are we really doing enough to

preserve this precious capital from the onslaught of a onesided science and its many irresponsible applications? Merely to preserve it is not suflicient. It must continually

be replenished with new life and created anew.

Our considerations have at more than one point taken

us to the boundary of philosophy and metaphysics.

This

happened so to speak against our will. We began by analysing the scientific method and the assumptions made,

and we examined the question of which natural phenomena

could be understood within the framework of these assumptions and which could not. We were forced to the conclusion that even quite simple natural phenomena fall outside this framework. These include all qualitative phenomena,

and here the philosophical question of the division between

subject and object at once arises.

They also most probably

include morphology and the evolution of living organisms,

and here teleology forces itself on us as an alternative or as

supplementary to causality. At the same time the metaphysical question at once arises of the origin of the set aim, of the being who prescribes the aims. As we have seen,

metaphysical questions arise even in connection with the

causal laws of contemporary science.

Thus the framework

of science can hardly be a completely closed framework; it is Opening up and requires to be opened up in various

directions, including that of metaphysics.

The sole purpose of this book has been to push open a

door;

a door

in a barrier

that surrounds

the region

of

validity of present-day science. For this purpose it was necessary first of all to see the barrier, and that is why we

had to concern ourselves so much with the assumptions that are made in science. On the far side of the barrier lies a wide terrain which is, scientifically speaking, practically

untrodden. There are indications that in bygone times men had occasional glimpses of this landscape (Pythagoras,

100

MAN

AND

SCIENCE

Plato) which were soon forgotten again, and completely lost under the impact of modern science.

We could not

attempt to cffect a synthesis between our science and this practically unknown territory.

This is a task for the future,

perhaps a remote future. It must suffice if we have at least succeeded in taking a fleeting glance through the open door without as yet being able to pass through it. Our point of view has always been from inside the barrier. The glance was however intended to show, at least in vague outline, some of the realities that exist and indeed particularly concern us as human beings, but which are outside of what

science treats nowadays or even regards as real.

They are

realities which give us an inkling of scarcely known—perhaps

previously surmised and now forgotten—spiritual facts and efficacies which have little in common with the clockwork

mechanisms we occupy ourselves with in science today. Of course we do not suggest that we could somehow

return to the older conceptions like those of Pythagoras and Plato. Our path can lead only by way of and beyond science. It will be the task of the future to find a way

through the door thus opened.

But it is only if even

now we clearly recognise, from our scientific standpoint, the existence of such realities, that we can succeed in escaping the barrenness of an extreme materialistic-

mechanistic view of the world. In this way only can we overcome the cleavage which the deep gulf existing today between man and his all-powerful about in ourselves.

science

has

brought