Table Of ContentPRELlJDE TO GAT.TT.EO
BOSTON STUDIES IN THE PHILOSOPHY OF SCIENCE
EDITED BY ROBERT S. COHEN AND MARX W. WARTOFSKY
VOLUME 62
WILLIAM A. W ALLACE
School of Philosophy, The Catholic University ofA merica, Washington, D.C.
PRELUDE
TO GALILEO
Essays on Medieval and Sixteenth-Century
Sources of Galileo's Thought
D. REIDEL PUBLlSHING COMPANY
DORDRECHT: HOLLAND / BOSTON: U.S.A.
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library of Congress Cataloging in Publication Data
Wallace, William A.
Prelude to Galileo.
(Boston studies in the philosophy of science ; v. 62)
Bibliography: p.
Includes indexes.
1. Astronomy, Medieval-Addresses, essays, lectures.
2. Astronomy -History-Addresses, essays, lectures.
3. Galilei, Galileo, 1564-1642-Addresses, essays, lectures.
1. Title. II. Series.
Q174.B67 voI. 62 [QB23] 501s [520'.9'02] 81-364
ISBN-\3: 978-94-009-8406-6 e-ISBN-13: 978-94-009-8404-2
DOI: 10.1007/978-94-009-8404-2
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EDITORIAL PREFACE
Can it be true that Galilean studies will be without end, without conclusion,
that each interpreter will find his own Galileo? William A. Wallace seems to
have a historical grasp which will have to be matched by any further workers:
he sees directly into Galileo's primary epoch of intellectual formation, the
sixteenth century. In this volume, Wallace provides the companion to his
splendid annotated translation of Galileo 's Early Notebooks: The Physical
Questions (University of Notre Dame Press, 1977), pointing to the 'realist'
sources, mainly unearthed by the author himself during the past two decades.
Explicit controversy arises, for the issues are serious: nominalism and realism,
two early rivals for the foundation of knowledge, contend at the birth of
modem science, OI better yet, contend in our modem efforts to understand
that birth. Related to this, continuity and discontinuity, so opposed to
each other, are interwoven in the interpretive writings ever since those
striking works of Duhem in the first years of this century, and the later
studies of Annaliese Maier, Alexandre Koyre and E. A. Moody. Historio
grapher as well as philosopher, WaUace has critically supported the continuity
of scientific development without abandoning the revolutionary transforma
tive achievement of Galileo's labors. That continuity had its contemporary
as well as developmental quality; and we note that William Wallace's Prelude
studies are complementary to Maurice A. Finocchiaro's sensitive study of
Galilea and the Art of Reasoning (Boston Studies 61, 1980), wherein the
actuality of rhetoric and logic comes to the fore.
William A. WaUace, O.P. was among the founders of our Boston Colloquium
for the Philosophy of Science, twenty years ago, when he was among the
scholar-priests at the Dominican House of Studies, then at Dover,
Massachusetts. We were grateful for his help then, and for his participation
in so many ways, including his lecture some years later on 'Elementarity and
Reality in Partide Physics' (Boston Studies 3, 1967). WaUace moves easily
and with justified confidence among medieval, renaissance, classical and
modem physics, as philosopher, historian, and philologist. We are grateful to
him once more for aU these qualities, evident in the essays of this book.
Center for the Philosophy ROBERT S. COHEN
and History ofS cience MARX W. WARTOFSKY
Boston University January 1981
TABLE OF CONTENTS
EDITORIAL PREFACE v
PREFACE ix
ACKNOWLEDGEMENTS xv
PART 1: MEDIEVAL PROLOGUE
1. The Philosophlcal Setting of Medieval Science 3
2. The Medieval Accomplishment in Mechanics and OptiC& 29
PART II: THE SIXTEENTH-CENTURY
ACHIEVEMENT
3. The Deve10pment of Mechanics to the Sixteenth Century 51
4. The Concept of Motian in the Sixteenth Century 64
5. The Calculatores in the Sixteenth Century 78
6. The Enigma afDominga de Soto 91
7. Causes and F orces at the Collegio Romano 110
PART III: GALILEO IN THE
SIXTEENTH-CENTURY CONTEXT
8. Galilea and Reasoning Ex suppositione 129
9. Galilea and the Thomists 160
10. Galileo and the Doctores Parisienses 192
11. Galilea and the Scotists 253
12. Gali1eo and Albertus Magnus 264
13. Galilea and the Causality of Nature 286
PART IV: FROM MEDIEVAL TO EARLY
MODERN SCIENCE
14. Pierre Duhem: Galileo and the Science ofMotion 303
viii TABLE OF CONTENTS
15. Anneliese Maier: Galileo and Theories of Impetus 320
16. Ernest Moody: Galileo and Nominalism 341
BIBLIOGRAPHY 349
INDEX OF NAMES 359
SUBJECT INDEX 365
PREFACE
Those acquainted with the literature on Galileo will recognize the kinship of
the studies contained in this volume, in style and content, with the colIec
tions produced by Pierre Duhem, Annaliese Maier, Alexandre Koyre, Ernest
Moody, and Stillman Drake. They represent the fruit of the author's labors
over a period of some fifteen years, much of which has appeared in journals
and proceedings that are not readily available to students of the history and
philosophy of science. In their elaboration, and particularly in the essays
written during the past several years (which make up the bulk of the volume),
the author has come to the conviction that Galileo wiU never be understood,
either historicalIy or philosophicalIy, when viewed in isolation from the
intellectuai background out of which his scientific work emerged. Galileo's
classics were written in the first part of the seventeenth century, but his early
studies and indeed his seminal work date from the last two decades of the
sixteenth century. The latter period has never been adequately treated by
historians of science; a [ortiori it has not been seen in its proper measure of
continuity with the centuries that preceded, extending back to the High
Middle Ages. The essays reproduced here aim to fiU this lacuna. Some have
been completely rewritten and alI have been reworked with this end in view,
so that effectively they present a unified thesis about the medieval and
sixteenth-century sources of early modern science. They are titled simply
Prelude ta Galilea, since the author does not wish to make exorbitant claims
about Galileo's "precursors," and yet wishes to signal the importance of the
studies for an understanding of Galileo's early, as well as his mature, contribu
tions.
The author's thesis departs in significant respects from those advanced by
the authorities already mentioned. With regard to Drake and to a lesser extent
Koyre, he believes that these writers, like most others who have written about
Galileo, have treated him a parte post and thus have evaluated him more from
hindsight than from a purview of the context in which his work developed.
Like the others mentioned - Duhem, Maier, and Moody - the author has
adopted the opposite perspective, one that is distinctively a parte ante. What
is particularly original about hls approach is that it focuses on hltherto
unknown manuscript sources of Galileo's late sixteenth-century notebooks,
ix
x PREFACE
and traces their lineage back to thirteenth-century thinkers, mainly scholastic
commentators on Aristot1e. The purpose of this tactic is not to make Galileo
a medieval, a scholastic, or an Aristotelian, but rather to flesh out the heritage
we now know to be his, one that he shared with few other professors at
Italian universities in the Renaissance. The author's thesis differs from those
of Duhem, Maier, and Moody main1y in that it does not accord fourteenth
century nomina1ism the key role in the genesis of modern science that they
do, but stresses instead the importance of more realist movements that
flourished from the thirteenth to the sixteenth centuries, viz, Thomism,
Scotism, Averroism, and Renaissance Aristotelianism generally. Some spec
ifics that serve to distinguish the author's position from those of Duhem and
Maier are set out in Essays 10, 14, and 15, while his critique of Moody's
collected essays is inc1uded as Essay 16.
The present work is further intended to serve as an interpretative volume
that draws out the historiographical and philosophical implications of the
author's Galileo 's Early Notebooks: The Physical Questions (Notre Dame:
The University of Notre Dame Press, 1977). Several of the essays in Parts I
and II were written while research for that book was in progress, and all of
those in Parts III and IV supply technica1 details and textual information
that authenticate and further explicate the materials contained in it. Where
feasible, these essays have been revised and keyed to the Notebooks so as to
facilitate the reader's reference to that work.
The studies in Part 1, entitled 'Medieval Prologue,' set the stage for appre
ciating the materials in the other parts. The first essay, 'The Philosophical
Setting of Medieval Science,' is adapted from the author's chapter of the same
title in a collection of essays edited by David C. Lindberg, Science in the
Middle Ages (Chicago: University of Chicago Press, 1978), pp. 91-119. The
second, 'The Medieval Accomplishment in Mechanics and Optics,' appeared
in slightly different form in the Dictionary of the History of Ideas, ed. P. P.
Wiener (New York: Charles Scribner's Sons, 1973), VoI. 2, pp. 196-205,
under the title 'Experimental Science and Mechanics in the Middle Ages.'
These essays document the main philosophica1 positions and scientific
contributions of the Middle Ages that are discussed in what follows, and thus
are essential for an understanding of the sixteenth-century development that
is central to the book's thesis.
Part II, 'The Sixteenth-Century Achievement,' contains, among others,
several paperS written while the author was pursuing studies of Domingo
de Soto. The first, 'The Development of Mechanics to the Sixteenth Cen
tury,' is adapted from an artic1e that appeared originally as 'Mechanics from
PREFACE xi
Bradwardine to Galileo' in the Journal of the History of Ideas 32 (1971),
pp. 15-28, and serves to establish continuity with several of the themes
developed in Part 1. The second essay, 'The Concept of Motion in the Six
teenth Century,' reproduces a study of the same title that appeared in the
Proceedings of the American Catholic Philosophical Association 41 (1967),
pp. 184-195. The third, 'The Calculatores in the Sixteenth Century,' is
revised slightly from 'The 'Calculatores' in Early Sixteenth-Century Physics,'
The British Journal for the History of Science 4 (1969), pp. 221-232. The
fourth, 'The Enigma of Domingo de Soto,' is adapted from an article with the
longer title, 'The Enigma of Domingo de Soto: Uniforrniter difformis and
Falling Bodies in Late Medieval Physics,' originally published in [sis 59
(1968), pp. 384-401. The last essay in this section, 'Causes and Forces at
the Collegio Romano,' is a somewhat different version of 'Causes and Forces
in Sixteenth-Century Physics,' [sis 69 (1978), pp. 400-412. This is the most
recent of the essays in this part and supplies material that is transitional to
Parts III and IV, delineating the contents of Jesuit teachings on motion that
show affmities with Galileo's early drafts on this subject, usually referred to
as theDe motu antiquiora.
Part III, 'Galileo in the Sixteenth-Century Context,' contains several ofthe
longest essays and is central to the thesis of the volume as a whole. Its first
essay, 'Galileo and Reasoning Ex suppositione,' appeared originally in the
Proceedings of the 1974 Biennial Meeting of the Philosophy of Science
Association, ed. R. S. Cohen et al. (Dordrecht-Boston: D. Reidel Publishing
Co., 1976), pp. 79-104, as 'Galileo and Reasoning Ex suppositione: The
Methodology of the Two New Sciences.' In view ofthe discussion this paper
has generated since its first publication, the author has added an appendix to
it for this volume, clarifying his positions on its key issues. The second essay,
'Galileo and the Thomists,' is heavily revised from the original version of the
same title, which was published in St. Thomas Aquinas Commemorative
Studies, 1274-1974 (Toronto: Pontifica1 Institute for Mediaeval Studies,
1974), VoI. 2, pp. 293-330. The third, 'Galileo and the Doctores Parisienses,'
is a reprint of an article of similar title that appeared in New Perspectives on
Galileo, eds. R. Butts and J. Pitt, Western Ontario Series in the Philosophy of
Science (Dordrecht: D. Reidel Publishing Co., 1978), pp. 87-138; it supplies
much of the textual documentation on which Galileo 's Early Notebooks is
based. An appendix has also been added to this essay analyzing additional
texts in which the Parisienses are cited, and thus further clarifying the sources
of Galileo's knowledge of this fourteenth-century nominalist school. The
fourth study, 'Galileo and the Scotists,' represents a fuller elaboration and
