The Nature of Natural Philosophy
in the Late Middle Ages
Studies in Philosophy and the
History of Philosophy
General Editor: Jude P. Dougherty
Volume 52
The Nature of Natural Philosophy
in the Late Middle Ages
Edward Grant
The Catholic University of America Press
Washington, D.C.
Copyright © 2010
The Catholic University of America Press
All rights reserved
The paper used in this publication meets the minimum requirements of American National Standards for Information
Science—Permanence of Paper for Printed Library Materials,
ANSI Z39.48-1984
∞
Library of Congress Cataloging-in-Publication Data
Grant, Edward, 1926–
The nature of natural philosophy in the late Middle Ages /
Edward Grant.
p. cm. — (Studies in philosophy and the history of
philosophy ; v. 52)
Includes bibliographical references and index.
ISBN 978-0-8132-1738-3 (cloth : alk. paper) 1. Science,
Medieval—Philosophy. I. Title. II. Series.
Q174.8.G725 2010
509.4ʹ0902—dc22
2009036242
Contents
Preface vii
Acknowledgments xv
1. When Did Modern Science Begin? 1
2. Science and the Medieval University 16
3.The Condemnation of 1277, God’s Absolute Power,
and Physical Thought in the Late Middle Ages 49
4.God, Science, and Natural Philosophy in the Late
Middle Ages 91
5.Medieval Departures from Aristotelian
Natural Philosophy 119
6. God and the Medieval Cosmos 140
7. Scientific Imagination in the Middle Ages 163
8.Medieval Natural Philosophy: Empiricism
without Observation 195
9. Science and Theology in the Middle Ages 225
10.The Fate of Ancient Greek Natural Philosophy in the
Middle Ages: Islam and Western Christianity 253
11.What Was Natural Philosophy in the Late
Middle Ages? 276
12.Aristotelianism and the Longevity of the
Medieval Worldview 312
Bibliography 327
Index 343
Preface
Until the early twentieth century, the expression “medieval science”
would have been regarded as an oxymoron. This changed when Pierre
Duhem, a famous French physicist, became interested in early science
and subsequently devoted himself to investigating what might have
passed for scientific activity during the Middle Ages. In his examination
of numerous medieval manuscripts by a variety of Scholastic natural philosophers, Duhem became convinced that there was indeed science in the
late Middle Ages. Between 1902 and 1916, he published some seventeen
volumes on medieval science and made the study of medieval science a
respectable research activity.1 He believed that the scientific activity he
had discovered in the Middle Ages played an essential role in producing
the Scientific Revolution of the seventeenth century. At the same time,
he also struck a blow for the continuity of the history of science, demonstrating that the period 1200 and 1500 in Western Europe was not a barren intellectual wasteland, as was almost universally assumed, but a fertile period that flowed naturally into the Scientific Revolution.
There is no doubt that Duhem sometimes made extravagant claims,
but his overall results were impressive. Later historians of medieval science, however, were not as certain as Duhem that medieval natural philosophy and science played a significant role in generating the Scientific
Revolution, but they were convinced that it probably played a positive
role. But historians of the Scientific Revolution would have none of
Duhem’s claims, or those made by subsequent historians of medieval
science. They accused medievalists of “whiggism,” or “presentism,” by
which they meant that medievalists viewed the science and natural philosophy of the Middle Ages with modern eyes, focusing on ideas and
achievements that sounded modern and could be interpreted as anticipa1. His most prodigious work was his ten-volume Le Système du monde. Histoire des doctrines cosmologiques de Platon a Copernic, 10 vols. (Paris, 1913–1959).
vii
viii Preface
tions of scientific ideas and theories that were actually proclaimed considerably later.
“Medieval claims were further subverted by Alexandre Koyré, a preeminent historian of the Scientific Revolution, who insisted that the classical science of the seventeenth century was in no way a continuation of
medieval physics, even when medieval ideas and concepts were strikingly
similar to ideas proposed in the Scientific Revolution. It was, he argued a
‘decisive mutation’ (mutation decisive). The ideas and concepts were embedded in radically different intellectual contexts. Or, to use the language
made famous by Thomas Kuhn in The Structure of Scientific Revolutions,
the respective normal paradigms of medieval and seventeenth-century
physics were incommensurable. The physics and cosmology of the Middle Ages, it was argued, were based wholly upon Aristotelian natural
philosophy, which was incompatible with the new science that emerged
in the seventeenth century. Indeed, Aristotelian natural philosophy was
viewed as the major obstacle to the birth of the new science. Only by its
repudiation could the Scientific Revolution have succeeded.”2 Many medievalists—including this author—accepted Koyré’s judgment about the
relationship of the Middle Ages and the advent of early modern science
in the seventeenth century. Although we argued that some interesting
contributions had been made in the Middle Ages, we regarded them as
playing little or no role in generating the Scientific Revolution. The difficulty of demonstrating that medieval scientific ideas had exerted any
direct influence on seventeenth-century natural philosophers led most
medievalists to cease making such claims. This attitude shaped my ideas
about medieval physical thought in my early book Physical Science in the
Middle Ages.3
But some fifteen to twenty years later, a stunningly dramatic question
occurred to me, one that changed my whole attitude about the relationship between medieval natural philosophy and early modern science:
could a Scientific Revolution have occurred in the seventeenth century if
the level of science and natural philosophy had remained what it was in
the first half of the twelfth century?
2. From my book, The Foundations of Modern Science in the Middle Ages (Cambridge:
Cambridge University Press, 1996), xii.
3. New York: John Wiley and Sons, 1971. Responsibility for the book was assumed by Cambridge University Press in 1977.
Preface ix
That is, could a scientific revolution have occurred in the seventeenth century if the massive translations of Greco-Arabic science and natural philosophy
into Latin had never taken place? The response seemed obvious: no, it could
not. Without the translations, many centuries would have been required before
Western Europe could have reached the level of Greco-Arabic science, thus delaying any possibility of a transformation of science. But the translations did occur and so did the Scientific Revolution. It follows that something happened between approximately 1200 and 1600 that proved conducive for the production
of a scientific revolution.4
This momentous question is equivalent to asking whether modern physics could have occurred in the nineteenth and twentieth centuries if the
level of physics was the same as it was in the days of Isaac Newton in the
seventeenth and early eighteenth centuries. The leap to modern physics
was a steady and gradual development. It could not have occurred by ignoring the many achievements and advances that had occurred between
Newton and the late nineteenth and twentieth centuries. The same could
be said of modern medicine and biology, and chemistry, and so on.
If the Middle Ages contributed to the revolution of early modern science, it did not do so by advances in the exact sciences, although some
significant contributions in physics and mathematics were made. Indeed, advances were also made in medicine and alchemy. Whether early
modern scientists and natural philosophers knew of these advances is
largely unknown. In truth, however, all this is largely irrelevant. I would
argue that in the Latin Middle Ages of Western Europe an intellectual
environment was established that proved conducive to the emergence of
early modern science. The new intellectual environment was generated
and shaped by “certain attitudes and institutions that were generated in
Western society from approximately 1175 to 1500. These attitudes and institutions were directed toward learning as a whole and toward science
and natural philosophy in particular. Together they coalesced into what
may be appropriately called ‘the foundations of modern science.’ They
were new to Europe and unique to the world. Because there is nothing to
which we can compare this extraordinary process, no one can say whether it was fast or slow.”5
4. Grant, Foundations of Modern Science, xiii.
5. Ibid., 170–71.
x Preface
Three of the most important preconditions that laid the foundations
of a new medieval intellectual world and made the Scientific Revolution
possible are: “(1) the translation of Greco-Arabic works on science and
natural philosophy into Latin, (2) the formation of the medieval university, and (3) the emergence of theologian-natural philosophers.”6 The
translations furnished scholars in the Latin West with Aristotle’s very
substantial body of natural philosophy and Averroes’s commentaries on
those works.
Aristotle’s works—especially his logic and treatises on natural philosophy—quickly formed the basis of an undergraduate education in the
newly formed universities of Paris and Oxford. By 1500 there were approximately sixty-five universities spread across Western Europe, virtually all of which taught logic and natural philosophy as the basic undergraduate discipline. Never before had a scientific subject such as natural
philosophy been disseminated so widely and deeply in any society. By
virtue of its emphasis on reason, natural philosophy made the use of reason commonplace in Western society, thus emphasizing one of the most
significant tools for the development of science.
Reason became of great significance in Western thought in part because Scholastics approached Aristotelian natural philosophy by framing questions. Commentaries on any of Aristotle’s books on natural
philosophy were in the form of a series of successive questions from beginning to end. The questions were answered by use of reason, and in the
fourteenth century, as a consequence of various articles condemned in
1277, use of the imagination was emphasized in counterfactual questions
about cosmic conditions and circumstances that were regarded as naturally impossible in Aristotle’s world.
I have used the expression “theologian-natural philosophers” because virtually all university-trained medieval theologians studied logic
and natural philosophy at whatever university they attended. They were
expected to be very familiar with natural philosophy. The importance of
the theologian-natural philosophers
cannot be overestimated. If theologians at the universities had decided to oppose Aristotelian learning as dangerous to the faith, it could not have become
6. Ibid., 171. For the present context, I have eliminated the word “the” before “theologiannatural philosophers.”
Preface xi
the focus of study in European universities. Without the approval and sanction
of these scholars, Greco-Arabic science and Aristotelian natural philosophy
could not have become the official curriculum of the universities.
To emphasize the great significance of the theologian-natural philosophers, I shall continue on from the passage just cited:
The development within the universities of Western Europe of a class of
theologian-natural philosophers was extraordinary. Not only did they endorse a
secular arts curriculum, but most believed that natural philosophy was essential
for a proper elucidation of theology. Schools of theology expected their entering
students to have attained a high level of competence in natural philosophy. As
evidence of this, students who wished to matriculate for a theology degree were
usually required to have acquired a master of arts degree. Because of the intimate relationship between theology and natural philosophy during the Middle
Ages and because arts masters had been forbidden by oath (since 1272) to treat
theological problems, it fell to the theologians to apply natural philosophy to
theology and theology to natural philosophy. Their training in both disciplines
enabled them to do so with relative ease and confidence, whether this involved,
for example, the application of science and natural philosophy to scriptural exegesis, the application of the concept of God’s absolute power to hypothetical
possibilities in the natural world, or the invocation of scriptural texts to support
or oppose scientific ideas and theories. Theologians had a remarkable degree of
intellectual freedom to cope with such problems and rarely allowed theology
to hinder their inquiries into the physical world. If there was any temptation to
produce a “Christian science,” medieval theologians successfully resisted it. Biblical texts were not employed to “demonstrate” scientific truths by appeal to divine authority.7
The points I have made in this preface are illustrated and discussed
in the essays that have been included in this book. In a certain sense,
these essays are all about natural philosophy and the role it played in
shaping medieval thought. The titles are sometimes good indicators of
what the essay discusses, as is true of “Science and the Medieval University,” “Medieval Departures from Aristotelian Natural Philosophy,”
“Scientific Imagination in the Middle Ages,” and “Science and Theology
in the Middle Ages.” Two articles—“When Did Modern Science Begin?”
and “What Was Natural Philosophy in the Late Middle Ages?”—describe
7. Ibid., 174, 175.
xii Preface
how natural philosophy played a significant role in producing the counterfactual questions that were proposed as a consequence of the articles
condemned in 1277. In “God, Science, and Natural Philosophy in the Late
Middle Ages,” I argue with those who believe that natural philosophy is
not in any way associated with science, because, as they argue, natural
philosophy is always about God and modern science is never about God.
“God and the Medieval Cosmos” and “Medieval Natural Philosophy:
Empricism without Observation” belong to the category of essays concerned with the substantive character of medieval natural philosophy as
manifested in its details. “The Fate of Ancient Greek Philosophy in the
Middle Ages: Islam and Western Christianity” attempts to show why natural philosophy in the West flourished while, in Islam, it lost its vitality
and gradually faded away. The final essay in this book—“Aristotelianism
and the Longevity of the Medieval Worldview”—seeks to explain how
medieval Aristotelian natural philosophy, and the view of the cosmos it
upheld for approximately five centuries, managed to remain the dominant way to interpret the world for so long.
I shall conclude my preface with a rather lengthy quotation from
the “Conclusion” of “What Was Natural Philosophy in the Late Middle
Ages?”8 It argues for the monumental importance of natural philosophy
for the history of science.
What was the legacy of medieval natural philosophy to the modern world? Before 1500, the exact sciences in Islam had reached lofty heights, greater than
they achieved in medieval Western Europe, but they did so without a vibrant
natural philosophy. By contrast, in Western Europe natural philosophy was
highly developed, whereas the exact sciences were merely absorbed (from the
body of Greco-Arabic scientific literature) and maintained at a modest level.
After 1500, Islamic science effectively ceased to advance, but Western science
entered upon a revolution that would culminate in the seventeenth century.
What can we learn from this state of affairs? Let me propose the following: that
the exact sciences were [changed from “are”] unlikely to flourish in isolation
from a well-developed natural philosophy, whereas natural philosophy is apparently sustainable at a high level even in the absence of significant achievements
in the exact sciences. One or more of the exact sciences, especially mathematics,
was practiced in a number of societies that never had a fully developed, broad8. History of Universities 20, no. 2 (2005): 39–40.
Preface xiii
ly disseminated natural philosophy. In none of these societies had scientists attained as high a level of competence and achievement as they had in Islam. Was
the subsequent decline of science in Islam perhaps connected with the relatively
diminished role of natural philosophy in that society and to the fact that it was
never institutionalized in higher education? This is a distinct possibility. In Islamic society, where religion was so fundamental, the absence of support for
natural philosophy from theologians, and, more often, their open hostility toward that discipline might have proved fatal to it and, eventually, to the exact
sciences as well.
Acknowledgments
The essays in this book were lightly edited for inclusion here. The work
was originally presented or published as follows:
1. “When Did Modern Science Begin?” The American Scholar (Winter
1997): 105–13. Reprinted in Frame and Focus: An Anthology for Investigative
Reading, edited by Paul Winters and James Schneider, 4th ed., 211–23. Boston:
Pearson Custom Publishing, 2004.
2. “Science and the Medieval University.” In Rebirth, Reform and Resilience: Universities in Transition 1300–1700, edited by James M. Kittelson and
Pamela J. Transue, 68–102. Columbus: Ohio State University Press, 1984.
3. “The Condemnation of 1277, God’s Absolute Power, and Physical
Thought in the Late Middle Ages.” Viator 10 (1979): 211–44.
4. “God, Science, and Natural Philosophy in the Late Middle Ages.” In Between Demonstration and Imagination: Essays in the History of Science and
Philosophy Presented to John D. North, edited by Lodi Nauta and Arjo Vanderjagt, 243–67. Leiden: Brill, 1999.
5. “Medieval Departures from Aristotelian Natural Philosophy.” In Studies
in Medieval Natural Philosophy, edited by Stefano Caroti, 237–56. Biblioteca di
Nuncius, Studi e Testi. Firenze: Leo S. Olschki, 1989.
6. “God and the Medieval Cosmos.” Public lecture at Harris Manchester
College Chapel, Oxford University, July 29, 1999.
7. “Scientific Imagination in the Middle Ages.” Perspectives on Science 12,
no. 4 (December 2004): 394–423. Copyright of Perspectives on Science is the
property of MIT Press, and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder’s express written
permission. However, users may print, download, or email articles for individual use.
8. “Medieval Natural Philosophy: Empiricism without Observation.” In
The Dynamics of Aristotelian Natural Philosophy from Antiquity to the Seventeenth Century, edited by Cees Leijenhorst, Christoph Luthy, and Johannes M.
M. H. Thijssen, 141–68. Leiden: Brill, 2002.
9. “Science and Theology in the Middle Ages.” In God and Nature: Historical Essays on the Encounter between Christianity and Science, edited by David
xv
xvi Acknowledgments
C. Lindberg and Ronald L. Numbers, 49–75. Berkeley and Los Angeles: University of California Press, 1986.
10. “The Fate of Ancient Greek Natural Philosophy in the Middle Ages:
Islam and Western Christianity.” The Review of Metaphysics 61 (March 2008):
503–26. Originally presented as a lecture at a conference titled “Children of
Abraham: Judaism, Christianity, and Islam,” Pennsylvania State University,
March 31–April 1, 2000.
11. “What Was Natural Philosophy in the Late Middle Ages?” History of
Universities 20, no. 2 (2005): 12–46.
12. “Aristotelianism and the Longevity of the Medieval World View.” History of Science 16 (1978): 93–106. Although considerably, and perhaps even radically, altered, preliminary versions of this essay were delivered at the banquet
of the eighteenth annual meeting of the Midwest Junto of the History of Science Society, March 26, 1976, University of Notre Dame; and again on November 4, 1976, at the Medieval Studies Conference, “Medium Aevum Transdisciplinale: Approaches to the Middle Ages,” Indiana University, Bloomington.
I am grateful to my colleague, Professor J. Alberto Coffa, who made valuable
suggestions for the improvement of this essay.
The Nature of Natural Philosophy
in the Late Middle Ages