The Birth of History and Philosophy of Science: Kepler's 'A Defence of Tycho against Ursus' with Essays on its Provenance and Significance 0521346991, 9780521346993

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Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

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Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Cambridge University Press 978-0-521-34699-3 - The Birth of History and Philosophy of Science: Kepler’s A Defence of Tycho Against Ursus with Essays on its Provenance and Significance N. Jardine Frontmatter More information

© Cambridge University Press

www.cambridge.org

Introduction

Kepler's A Deftna of Tycho against Ursus (Apologia pro Tychont contra Ursurn), written around Christmas 16oo, offers much more than the title suggests. To counter Ursus' denial of the capacity of astronomers to •portray the form of the world' Kepler provides an elaborate defence of astronomy against a variety of cogent sceptical ploys. And to refute the history of astronomical hypotheses by which Ursus had sought to discredit Tycho Brahe's claims to originality, Kepler provides a selective history of world-systems &om Zoroaster and Pythagoras to Copernicus and Brahe. The rebuttal of scepticism in astronomy is a tour dt force, efficient and witty in its refutation of Ursus' arguments and striking in its apparent anticipations of strategies used in the present century in defence ofscientific realism. Parts of his history of astronomy, notably his examination of Apollonius of Perga's models for the second anomaly and his attempts to trace a classical pedigree for geoheliocentric cosmology back from Martianus Capella to Plato, remain of interest to present-day historians of the subject. Further, the work is of considerable importance for Keplerian scholarship. Kepler is unusual amongst the major mathematical scientists of his period in the depth of his engagement in epistemological and methodological issues. All his major astronomical works are enlivened by such philosophical reflections. But the Apologia is his only extended treatment of these topics. As such it provides many keys to the understanding of the theory and practice of inquiry that inform both his earlier Mysttrium cosrnographicum and his mature masterpieces, Astronomia nova, Harrnonice rnundi and Epitomt astronorniat Coptrnicanat. The Apologia is a work of great originality not only in its theses, but also in its concerns. Kepler focusses throughout the work on theoretical progress in the history of astronomy and the means whereby such progress may be achieved. Concern with theoretical progress is prevalent at every level, historical and philosophical, academic and popular, of modem reflection on the natural sciences. Yet in this respect the Apologia appears to be without substantial precedent in sixteenth-century writing on the epistemology and history of the mathematical arts. Claims about the origins of genres and I

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Introduction disciplines inevitably oversimplify complex processes and are vulnerable to the discovery of earlier documents. Nevertheless I conjecture that if any one work can be taken to mark the birth of history and philosophy of science as a distinctive mode of reflection on the status of natural science it is Kepler's

Apologia. The Apologia remained unpublished until 1858. 1 Since then it has received only a modicum of scholarly attention. An early reaction was that of Karl von Prantl, who praised the first chapter for its exposition of a sober inductive methodology in sharp contrast to the 'fantastic' theological and metaphysical speculations of the Mysterium and Harmonice. 2 Ernst Cassirer, a far more sensitive reader, saw in the work a ·plea for the grounding of astronomical hypotheses in physics and metaphysics of the kind which Kepler had attempted in his Mysterium and was to elaborate in his later works.J And Pierre Duhem in his influential essay To Save the Phenomena identified the clash between Ursus and Kepler as an instance of a long-standing confrontation between sound instrumentalist and unsound realist conceptions of the mathematical sciences.• Amongst the few more recent appreciations of the epistemology of the work, those of Ralph Blake, Jurgen Mittelstrass, Bob Westman, Eric Aiton and the author have all, following Cassirer rather than von Prantl, found in the Apologia a methodological stance which illuminates the practice of Kepler's major astronomical works; and they have variously emphasised the importance.and originality of Kepler's views on the status of astronomy and on the means· whereby theoretical disputes in astronomy may be resolved. 5 Reactions to KeP.ler's history of astronomy have tended to concentrate on isolated passages which cast light on issues in Copernican ' C . Frisch, ed., Joa11nis Kq>ltri astronomi op~a omnia, i (Frankfurt and Erlangcn, 18s8-71), 1, 236--]6. Hereafter cited as K.o.o. 2 K. von Prantl, 'Galilei und Kepler als Logikc:r', Sitzungsbtrichtt dtr philosophuchephilologischtn und historischtn Klasst dtr k .b. Akadtmit dtr Wissen.scluiften z u Miinchen (181sl. 394- 408. ' E. Cassircr, Das Erkenntnisprobltm in dtr Philosoph~ und W isstnscluift dtr ntutrtn Ztit, 1 (Berlin, 1906), 262- 4. • P. Duhem, IDZEIN TA