Perception

Citation preview

PERCEPTION by

H. H. PRICE Wykekam Professor o f Logic in the University o f O xford

M E T H U E N & CO. LTD . 36 Essex Street, London W .C .i

F irst Published M ay rgth 1932 Reprinted zuiih minor corrections (Second Édition) J u ly 1930 Reprinted 1954 and 196 1

2 .3

CATALOGUE NO. 2/5142/IO Princed by photo-lithography at the Pitman Press, Bath and bound by Jamas Burn & Co., London

PREFACE HIS book is the successor of a dissertation submitted for the B.Sc. Degree in Oxford in 1922; but since then it has been entirely re-cast, so that little if anything of the original survives. I need hardly say that it does not profess to cover the whole of the subject suggested by the title. It is concerned in the main with only two points, the nature of perceptual consciousness and the relation of sense-data to the ordinary ‘ macroscopic objects' of daily life, such as tables and rocks. On both those ponts what may be called a causal theory has long been prevalent. It has been held that sense-data are related to material things merely by a rela.ti.on of indirect causal dependence (sometimes resemb­ lance has been added.) ; and that perceptual consciousness either is, or at any rate ought to be, an argument from effects to causes. This theory has of course been attacked, almost from its beginning, by a long and illustrious series of philo­ sophers, from Berkeley to Mr. Bertrand Russell (in his middle period) ; and its hold upon educated opinion has been further weakened of late years by the spread of the ‘ descriptive ’ view of Science. But it is still so widely held, both by philo­ sophers and non-philosophers, and indeed has so many perfectly legitimate attractions, that one more attempt to replace it by something less violently opposed to Common Sense may not be a waste of time. At any rate, I am convinced that the theory is radically mistaken, and my main aim in this book, whether worth achieving or not, is to present a constructive and detailed alternative to it. If in so doing I seem to have inclined too much to the opposite or Phenomenalistic extreme, I can only plead that at least this is by far the lesser evil. The main arrangement of the book is as follows. Chapter I is cliiefly introductory, and seeks to establish the reality of sensing and of sense-data. In chapter II, after stating the main problem, which is arrived at by considering the various meanings of the word ‘ perceive’, I proceed at once to expound

T

vi

PERCEPTION

and discuss a number of answers to it which. I hold to be erron­ eous : first Naïve Realism, both in its pure form, and in its more subtle modern modifications (chapters II and III) ; and then the Causal Theory (chapter IV) which I have stated as sympathetically as I can, and in more detail than is customary, in order to give it a fair run for its money. Chapter V is a sort of interlude on the nature of sense-data, or as it is some­ times called, their ontological status. In chapters VI and VII I have tried to give a description of our ordinary everyday perceptual consciousness (this must be sharply distinguished from the sensing by which it is accompanied and conditioned). I have tried to show that it has its own criteria of validity, and that no external ones are either necessary or possible. In this connexion I wish to lay particular stress upon the fact that perceptual consciousness has two distinct grades, which I have called perceptual acceptance and perceptual assurance ; the difference between them -has not, I think, been always recognized. The subsequent chapters (VIII to X) are devoted to the relation between sense-data and material things, which following Professor G. E. Moore I have called the relation of belonging to. This has involved me in a complex and I feax somewhat tedious investigation of the relation of sense-data to one another, the chief aim of which is to set clearly before the reader's mind the notion of a family of sense-data. Throughout this part of the book, as will be obvious to the judicious student, I am very greatly indebted to the writings of Professor G. E. Moore, Mr. Bertrand Russell, and Dr. C. D. Broad ; but indeed their influence extends, in an only slightly diminished degree, to the earlier chapters as well. In these later chapters, and to some extent in the earlier ones also, I have ventured to introduce a certain number of new technical terms. This may distress some readers, but I think it should assist most, for at least circumlocution is avoided and criticism facilitated. I have done my best to state clearly what they mean, and indeed in most cases their meaning is obvious. Where they are inadequate perhaps they may stimulate some one to produce better ones. In any case, nobody is obliged to use them if he does not want to. In conclusion I am bound to make grateful acknowledg­ ments to friends, teachers and colleagues, senior and junior, both in Oxford and in Cambridge, to whom I owe both my interest in this subject and my power to pursue it : in Oxford, to Mr. H. W. B. Joseph, Professor H. A, Prichard and Professor

vii

PREFACE

J. A. Smith, and among my own contemporaries to Mr. Gilbert Ryle, Mr. J. D. Mabbott and Dr. A. C. Ewing ; and in Cam­ bridge to Professor G. E. Moore and Dr. C. D. Broad. I have already mentioned my debt to the writings of Dr. Moore and Dr. Broad, which are familiar to all English-speaking students of Perception ; but thanks to their own kindness, and the generous hospitality of Trinity College, Cambridge, I. have also had the privilege of attending their lectures, and the still greater privilege of private discussion with them. I wish I could think that I had made due use of these advantages. H. H. PRICE T r in it y C o l l e g e , O x fo r d

March, 1932

PR EFACE TO 1954 R E PR IN T h is reprint of Perception is not a new edition. Apart from a number of minor verbal changes and the correction of some misprints, the book remains as it was when it first appeared more than twenty years ago. A second edition would require such drastic re-writing of the present text that the result would be a new book, treating the subject on quite different lines. If I were to undertake the task, I should try to state a theory of perception much more ‘ Realistic’, much less close to Phenomen­ alism, than the one which is expounded here. In the present book, the fundamental concept is that of a sense-datum; and during the last twenty years, the sense-datum analysis of perception has been very severely criticized by a number of distinguished writers. With many of these criticisms I agree, but not with all of them. I still think that the sensedatum terminology is useful for purposes of phenomenological description, where our aim is to describe how things look (sound, feel, etc.) and not how they physically are. E03LESam.piaJ.llfi world as a

T

scuse-data or something like it. Moreover, it is a strange misunderstanding to assume, as some eminent thinkers have, that visual sense-data must be ‘ flat’, i.e. two-dimensional. It is a plain phenomenological fact that visual fields have the

viii

PERCEPTION

property of depth. And why should the sense-datum philo­ sophers, of all people, be supposed to deny this obvious fact? On the contrary, they have usually been careful to emphasize i t ; and in this book it is emphasized ad nauseam. Again, it has sometimes been assumed that according to the sense-datum philosophers, our ordinary perceptual experience consists of nothing but the sensing of various sorts of sense-data. But this is not what the sense-datum philosophers maintain. They hold that the sensing is normally accompanied by something else, called 'perceptual acceptance’ in this book— the belief or the taking for granted that the sense-data we are aware of belong..t,CLmaiemLohj£cr.s. Nevertheless, I agree with the critics that the sense-datum analysis is not the best starting-point for a discussion of normal perception. A terminology devised for describing the way things look, as distinct from the way they physically are, may lead us to treat all perceptual experiences as if they were illusory or hallucinatory ones; and thereby (like its predecessor, the terminology of 'id eas’) it m ay lead us to doubt whether per­ ception can ever give us any knowledge of the material world at all. We may come to feel that we are irremediably cut off fro m the material world bv an ‘ iron curtain' of sense-data. But there seems to be something logically incoherent about such scepticism. To make someone understand the sense-datum terminology, we have to give him suitable instructions. ‘ Look at a pencil. Push one of your eyes aside with your finger. There will now be two elongated colour-expanses in your visual field, whereas there was only one before. These two colour-expanses are visual sense-data.’ The words I have italicized are material object words, belonging to the everyday material-object vocabu­ lary of common sense. The same might be said of the command ‘ look at’, with which the instructions began. It is naturally taken to mean 'direct your eyes towards’. If these instructions, and others like them, are to be understood, the material-object language of common sense must be understood already. And how can we have learned to understand it, unless some materialobject words have ostensive definitions? To say the same thing otherwise, it-would seem tha,L.a.t least. some material-__ object concepts must be empirically cashable bv a direct awareness of the objects which are instances of them. In that case, there must surely be something wrong with the sceptical doubts into which the sense-datum terminology (when once we have learned to use it) is liable to lead us. If the doubts

PREFACE

ix

had been well-founded, the terminology itself could, never have been understood. I am inclined to agree with another point on which the critics of sense-d.ata have insisted. They contend that in ordi- . narv perceptual experience we are never aware of sense-data a,t all; that an ordinary perceptual experience is just an awareness of material objects and physical happenings, such as clouds, trees, and thunderclaps. On this view, what the sense-datum philosophers call 'sensing’ and take to be a constituent of all perceptual experience, should rather be called phenomenological inspection. The attitude of phenomenological inspection, it would be said, is only attainable by a very con­ siderable voluntary effort, and is something quite outside the experience of the ordinary percipient. But unless we can manage to get ourselves into this special attitude (and. even some philosophers, it would seem, are incapable of doing so) we shall not be able to notice the facts which the sense-datum theorists are trying to describe. It does not, of course, follow from this that the facts are not there to be noticed, nor that they are unimportant, nor that a terminology designed to describe them is useless. But it does follow that a terminology, or a conceptual apparatus, which is suited for this special purpose is not the appropriate one to use when our aim is to analyse ordinary perceptual experience. Nevertheless, despite the force of these criticisms, I hope that the book may still have some value as it stands. It may serve at least as a useful Aunt Sally, and beginners may exercise their minds by detecting its inadequacies. It may have a certain historical interest, as a typical product of a now remote philosophical epoch. Its whole approach to the problems of perception may be misguided, or over-narrow, or just mistaken. But the reader may still learn something by seeing what this approach leads to, when an attempt is made to work out its implications in detail. The central concept of this book, the concept of a sense-datum, may be regarded as an analytical tool. The value of such a tool cannot be judged by a priori arguments. The only way to judge it is to see what clarificatory (or obfuscatory) power it shows when it is actually applied. H. H. PRICE

CONTENTS CHAP.

PAGE

P

reface

I II III

.

The Gi

N a ïv e R

. v

.

e

e a l ism

.

th e

S o m e M o d if ic a t io n s

of

A

N a Tv e R

T

he

Ca u sa l T

V

T

he

N a t u r e o f S e n s e -D a t a

Perceptual ance

V II

P

erceptual ance

V III

IX X

T

h eo ry

.

.

21 55

e a l is m

.

I.

.

.

.

.

P erceptual

103

A ccept­

139

.............................................................. ............ C o n s c io u s n e s s .

II.

P erceptual

A ssu r ­

....................................................................................................170 e l a t io n

of

S e n se -D a t a

to

One A

T he- R

e l a t io n

of

S e n s e -D a t a

to

M atter

T h e O r ig in a t io n Index

v

I l l u s io n

R

he

.

.............................................................. . 6 6

C o n s c io u s n e s s .

.

.

r gu m ent prom

IV

VI

.

....................................................................................... i

n

and

.

.

.

S e n s e -D a t a

of

.

.

xi

.

. .

nother

.

. .

. .

. .

.

204

.

273 309 323

PERCEPTION CHAPTER I THE GIVEN V E R Y man entertains a great number of beliefs concern­ ing material things, e.g. that there is a square-topped table in this room, that the earth is a spheroid, that water is composed of hydrogen and oxygen. It is plain that all these beliefs are based on sight and on touch (from which organic sensation cannot be separated): based upon them in

E

the.sen^thatii,j^Aad.aot.hMxextam.piartfc^r.exp£xiences