Science in Christian Perspective


A reply to David Siemens and others


From: JASA 20 (September 1968): 87-91, 97.


Ignorance of the history of science has been the greatest stumbling-block for many who have attempted to describe the relationship between the Protestant Reformation and scientific developments of the 16th and 17th centuries. Non-historians of science, blissfully uninformed, rhapsodize about the transformation of scientific thought that occurred during this period, convinced not only that something dramatic happened, but also that they know what it was. This is the time, they tell us, when modern science began: Copernicus threw off the fetters of ancient astronomical systems; Galileo rejected Aristotelian physics and the scholastic method of disputation in favor of the teachings of the senses; finally, Newton brought intelligibility to the universe by formulating a science based upon mathematical law.

And what was the cause of this great awakening? Protestant writers have generally seen it as a product of the Reformation; Catholics have been more prone to stress the Christian world view in general; nontheists have tended to see it as an expression of a new "hedonist-libertarian spirit" of the Renaissance.1 In the present paper, I am interested primarily in the former point of view, which I can illustrate with a sampling of recent claims. John Montgomery has written that "the simultaneity of the Copernican and Lutheran revolutions suggests a more than accidental relationship between them."2 Henry Stob concludes that "it was Christianity that supplied the firm foundation for modem natural science, and that the Reformation was used by God so to delineate this foundation as to dispose men to build on it the vast new structure of science.3 David Siemens has written in the ASA journal that "it is a matter of record that science never developed anywhere except where there was Christian influence. . . . And it is also enlightening to note that the extension of science came mainly in the areas where the Bible was most often and freely read."4 Finally, Robert K. Merton, author of the classic statement regarding the relationship between science and the Reformation, argued some years ago that, while Puritanism did not generate empiricism and rationalism, it sanctioned an empirical approach to nature and

*David C. Lindberg is in the Department of the History of Science, The University of Wisconsin, Madison, Wisconsin.

thereby "made an empirically founded science commendable rather than, as in the medieval period, reprehensible
. . . . "5

The trouble with such views is that they are based on old stereotypes regarding the origin of modem science in the 16th and 17th centuries. If indeed one can discover in the scientific thought of this period a radical discontinuity inexplicable in nonreligious terms, then it is plausible, (though still not proved) that Christianity in some way served as the ground out of which this new science grew. Such is the contention of David Siemens, who believes that Galileo "is the man basically responsible for the founding of modem science," and that Galileo's thought, in turn, was nurtured in essential ways by Hebrew-Christian traditions.6 Pronouncements of this kind are reassuring to the Christian community and always find, a receptive audience, but, alas, they are false. They ignore the last half-century of research in the history of medieval and early modem science; they presuppose a pattern of development in 16th and 17th century science that simply did not occur.

Presumably my view of what did occur is called for at this point. Unfortunately, this is a question far too complex to be settled here. But perhaps I can achieve some of the same goals by undertaking the much more limited task of stating some of the things that the scientific revolution was not.


In the first place, during the 16th and 17th centuries there was little in the way of a radical theoretical break with the scientific thought of antiquity and the Middle Ages. On the contrary, recent research in the history of science has demonstrated the remarkable extent to which 16th and 17th century science grew out of and was continuous with strong Greek and medieval traditions.7 If, for most of us, the intuitive impression that there was something dramatically different about the 16th and 17th centuries still lingers, this is simply because our preconceptions have been shaped by centuries of ignorance regarding ancient and medieval science.

Consider, for example, the Copernican reform of astronomy.8 Not only was its motivation conservative reform7but Copernicus' astronomical criteria and heliocentric hypothesis were entirely of ancient origin.

In his De revolutionibus, Copernicus describes in unambiguous terms his reasons for attempting an astronomical reform: (1) he was unhappy about the inability of the Ptolemaic system to "save the phenomena" exactly; (2) he was dissatisfied with the unsystematic character of Ptolemaic astronomy; and (3) he regarded the equant, which violated the ancient criterion of uniformity as abhorrent.9 The first requirement, that of saving the phenomena, had been an essential element in astronomy since antiquity, and Copernicus was merely expressing the frustration that had been growing among astronomers for centuries and that had been communicated to him by his teachers at Cracow and Bologna in the 1490's.10 But what of his other two reasons? Why should he have placed so much stress on system and uniformity? Very simply because during his student days at Cracow he had come under the influence of Neo-Pythagoreanism through the works of Marsilio Ficino and a Platonic society known as the "Brotherhood of the Vistula."" As a result of these influences, Copernicus applied Pythagorean criteria to the heavens from the very beginning of his astronomical career: thus nommiformity in the form of the equant must be purged; arbitrary elements in Ptolemaic astronomy must be dealt with by drastic means; the universe must be harmoniously ordered. Among the most significant results of the application of this Pythagorean outlook was Copernicus' decision to locate the sun, which was an object of worship among Neo-Pythagoreans, in the central place of honor. His rapture over the result speaks volumes:

In the middle of all sits Sun enthroned. In this most beautiful temple [i.e. the universe] could we place this luminary in any better position from which he can illuminate the whole at once? He is rightly called the Lamp, the Mind, the Ruler of the Universe; Hermes Trismegistus names him the Visible God, Sophocles' Electra calls him the All-seeing. So the Sun sits as upon a royal throne ruling his children the planets which circle round him.12

Nor are the personal terms used to describe the sun merely figurative; for Copernicus, as for the Pythagoreans, the sun is alive and divine.

So much for the astronomical criteria applied by Copernicus. Where did he get his idea of the structure of the universe? Again from the ancients:

I pondered long upon this uncertainty of mathematical tradition in establishing the motions of the system of the sphere.... I therefore took pains to read again the works of all the philosophers on whom I could lay hand to seek out whether any of them had ever supposed that the motions of the spheres were other than those demanded by the mathematical schools [i.e. the Ptolemaists]. I found first in Cicero that Hicetas had realized that the Earth moved. Afterwards I found in Plutarch that certain others had held the like opinion. . . . Taking advantage of this I too began to think of the mobility of the Earth . . . . 13

Indeed, Copernicus appears to have been aware of the complete beliocentric system devised by Aristarchus of Samos in the 3rd century B.C.; before his De revohitionibus went to press, he suppressed the following passage:

Though the course of the Sun and Moon can surely be demonstrated on the assumption that the earth does not move, it does not work so well with the other planets. Probably for this and other reasons, Philolaus [a Pythagorean] perceived the mobility of the earth, a view also shared by Aristarchus of Samos.14

It is clear, then, that Copernicus was attempting no more than a purification of astronomy by a return to the astronomical and metaphysical principles of antiquity. The only thing revolutionary about his work was its long-range impact; one historian has aptly written of "the Copernican Revolution, to which Copernicus was not party."15

If Copernicus was indebted to ancient Greece, Galileo was indebted to medieval Europe. On the problem of falling bodies, where his greatest fame has rested, Galileo for the most part merely restated medieval conclusions. For example, his distinction between kinematics and dynamics, his definitions of instantaneous velocity and uniformly accelerated motion, his statement of the mean-speed theorem and the odd-numbers law,"16 and his graphical demonstration of the latter two theorems were all drawn from 14thcentury traditions at Oxford and Paris. Galileo's only original contribution seems to have been his demonstration, employing the inclined plane, that freely falling bodies are instances of uniformly accelerated motion -though even that conclusion had been reached and published (probably unknown to Galileo) more than fifty years earlier by Domingo de Soto, a Spanish Dominican.17

Further examples of continuity between ancient, medieval, and early modern scientific thought are abundant and could be drawn from such fields as chemistry, medicine, optics, and magnetism.18 Perhaps, however, the two instances discussed will suffice to illustrate the general point: the dramatic theoretical discontinuity that historians-and more especially non-historians and poorly informed historians-have perceived between ancient, medieval, and early modern science has been grossly exaggerated. Those who would continue to bold the contrary are forced consistently to ignore, downgrade, or find some subtle deficiency in ancient and medieval scientific thought.


Secondly, the 16th and 17th centuries saw no radical methodological break with Antiquity and the Middle Ages. I am well aware that such a statement may startle readers nourished on the popular stereotypes and clich6s. In the popular view, science languished during the Middle Ages as scientists engaged in futile logic-chopping. In due time, however, scientists perceived the need for a new method that would include mathematical and experimental elements; the introduction and development of this method by Francis Bacon, Galileo, and Newton finally ushered in modem science.

Such a description is a travesty on the actual development of science. Mathematical and empirical elements were neither totally lacking from the methodology of ancient and medieval science nor universally present in the methodology of the 17th century. As Crombie and Randall have argued, 17th-century methodologists (and Bacon in particular) refined, but did not substantially alter the methodologies formulated during the Middle Ages-and, indeed, similar discussions had been continuous since the time of Aristotle.19 Thus Robert Grosseteste (d. 1253) and a host of followers discussed the formulation of generalizations by a process of induction, followed by the deduction of particulars from those generalizations for the purpose of experimental verification or falsification. In this twofold process, mathematical description was frequently held to play an essential role.10 Crombie concludes that "the conception of the logical structure of experimental science held by such prominent leaders as Galileo, Francis Bacon, Descartes, and Newton was precisely that created in the thirteenth and fourteenth centuries ."21

However, we are more concerned with the actual method employed by working scientists than with that described in abstract methodological treatises. Is it not true that this methodology, shared in common by medieval and l7th-century scientist, was practiced only by the latter? It is dangerous to generalize on the method employed by ancient, medieval, or 17th century scientists; but it is reasonably certain that none of them ever employed the method formulated abstractly in a tractatus de methodo. The safest generalization one can make is that all employed methods appropriate to the questions they were asking. Consequently, in all periods we find an overwhelming variety of methods; and in no period were those elements traditionally regarded as characteristic of the 17th century utterly lacking. One need only mention the optical work of Ptolemy, Ibn al-Haitham, and Theodoric of Freiberg (a Greek, a Muslim, and a 13th-century Dominican) as illustration.22 If there was a growing employment of experiment in the 17th century, it was not because scientists had finally recognized the need for a new and more fruitful method, but because mechanistic natural philosophy increasingly raised questions to which experiment was capable of giving an answer. As A. R. Hall has written with such perception, "The critical feature of seventeenth-century science was that it embraced new or revived ideas.... If anything, empiricism was adopted because it offered some promise of verifying these ideas."23

Consequently, it is absurd to maintain, as Siemens has, that "it is a matter of record that science never developed anywhere except where there was Christian influence."24 Such a claim utterly ignores the scientific achievements of Greeks like Aristotle, Galen, Ptolemy, and Archimedes; of Muslims like Ibn Sina, Ibn alHaitham, Kamal al-Din al-Farisi, and Ibn Badga. Indeed, it is difficult even to know what such a claim means. If Siemens is asserting that no scientist deprived of Christian influence engaged in the kinds of activities that characterize modem science or achieved any scientific conclusion of value, he is plainly mistaken. If, on the other hand, he is asserting that no such scientist discovered the whole truth about anything, then one must reply that neither did Newton. Finally, if Siemens intends that no large and vigorous scientific community developed outside of Christendom, two responses are possible: first, one can simply point to the activity at Aristotle's Lyceum or Hellenistic Alexandria and the Museum; secondly, if those are not sufficiently large scientific communities to satisfy Siemens, one can turn Siemens' sword around and thrust in the opposite direction, noting that nuclear warfare was never developed outside of Christendom either-which is simply to say that Christianity is not to be credited with everything that has. occurred in Christendom.


In the third place, scientific progress in the 16th and 17th centuries did not spring from the idea that nature could be rationally comprehended. If we must generalize, it is the contrary that is true. According to Siemens, "It was their belief in the incomprehensibility of the universe-excepting the heavens- that blocked both Greeks and Chinese from searching for a rational order in the material universe . . . . ... 25 Whatever may be true of the Chinese, Siemens' claim is not true of the Greeks. From Greek antiquity through the Middle Ages, the central aim of science was to gain an understanding of the essence of nature; as Aristotelians were prone to express it, one must proceed by induction from that which is "first in the order of knowing," i.e. from sense data, to that which is "first in the order of nature." The fundamental presupposition of this endeavor was that the underlying reality could be comprehended by the human intellect with absolute certainty. (It went without saying that the phenomena were susceptible to description.) This point is well illustrated by E. J. Dijksterhuis in his evaluation of Aristotelian natural philosophy:

That he and his predecessors, on the ground of certain superficial sense-experiences . . . proceeded so readily to frame a theory of such general character, and that his successors accepted this theory so eagerly and uncritically, illustrates again the tendency, already noted among Greek thinkers generally, to underestimate the difficulty of studying nature. No matter whether they took a more or less empirical attitude towards nature, without a single exception they overrated the power of unchecked speculation in natural science.26

Thus if there was too little experimentation in antiquity, it was because Greek scientists felt that nature was so transparent to the human intellect that laborious empirical investigation was unnecessary. They had, not too little confidence in the ability of the human mind to penetrate nature, but too much.

This ancient ideal of science continued to hold sway in the first half of the 17th century. Francis Bacon and Descartes underestimated the complexity and opacity of nature; like Aristotle, their goal was to penetrate with absolute certainty to the ultimate reality.27 Descartes could argue, for example, that the essence of matter is extension; matter, for him, was not an incomprehensible "given," as it was to become later in the century, but an entity capable of complete comprehension and precise definition. However, by the middle of the century the skeptical crisis, brought on by a number of factors including the existence of competing philosophies and the recovery of the works of the ancient skeptics in the latter half of the 16th century, had shattered man's confidence in his intellectual powers and the comprehensibility of nature.28 It is legitimate, therefore, for the scientist to restrict
In Pierre Gassendi, one of the first scientists to accept himself to a mathematical description of the
the conclusions of skepticism, we see the dim outline phenomena. There is no more characteristic feature of
of a new aim for science. Walter Charleton, speaking for Gassendi, writes:

That the sounding line of man's reason is much too short to profound the depths or channels of that immense ocean, nature,
needs no other evictment but this, that it cannot attain to the bottom of her shallows. It being a discouraging truth, that even  those things which are familiar and within the sphere of our sense, and such to the clear discernment whereof we are
furnished with organs most exquisitely accommodated, remain yet ignote [i.e. unknown] and above the moon to our under standing.29

For insomuch as the true idea of nature is proper only to that Eternal Intellect which first conceived it, it cannot but be one of the highest degrees of madness for dull and unequal man to pretend to an exact or adequate comprehension thereof.30

If man's reason cannot plumb the depths, or even the shallows, of nature, what shall he do? He must restrict
himself to a description of the surface appearances. Thus Charleton continues:

We need not advertise that the zenith to a sober physiologist's [i.e. physicist's] ambition is only to take the copy of
from her shadow, and from the reflex of her sensible operations to describe her in such a symmetrical form as may appear most plausibly satisfactory to the solution of all her phenomena.31

To a considerable extent Gassendi and Charleton for the 18th and 19th. Indeed, already in the 1630's, Galileo had expressed the same point in his analysis of falling bodies; gravity is beyond comprehension, and therefore one must restrict himself to a description of the phenomena:

But we do not really understand what principle or what force it is that moves stones downward, any more than we under stand what moves them upward after they leave the thrower's hand, or what moves the moon around. We have merely . . .assigned to the first the more specific and definite name gravity,' whereas to the second we assign the more general term 'impressed force 32

At present it is the purpose of our Author [i.e. Galileo] merely to investigate and demonstrate some of the properties of accelerated motion (whatever the cause of this acceleration may be)... 33

The notebooks of the young Newton reveal that he was heavily influenced by Gassendi and Charleton.34 Thus very early in his career he adopted Gassendi's restrictions on the possibility of knowledge as well as this mechanistic natural philosophy. This outlook explains Newton's extreme caution in expressing hypotheses regarding the cause of gravity. He knew that his inverse-square law was an description of the phenomena, but he recognized the impossibility of achieving equal certainty regarding the cause. Thus Newton writes that he "feigns no hypotheses" and that

hitherto we have explained the phenomena of the heavens and the cause of this power. . . . To us it is enough that gravity does really exist, and act according to the laws which we have explained, and abundantly serves to account for all the motions of the celestial bodies.35

Newton here reflects the influence of skepticism. The human mind is unable to penetrate to the ultimate reality; nature is essentially opaque to human reason. It is legitimate, therefore, for the scientist to restrict himself to a mathematical description of the phenomena. There is no more characteristic feature of Newton's philosophy of nature.36


Finally, I must append a note of caution and clarification. I am not to be interpreted, in the foregoing argument, as maintaining complete continuity between medieval and early modem science. On the contrary, I regard it as quite legitimate to speak of a "scientific revolution" in the 16th and 17th centuries. My point is rather that the actual discontinuities between medieval and early modem science are not those traditionally assigned, and particularly not the three considered above; nor are they, in any meaningful sense, Christian in origin. Perhaps, in order to clarify,  I might be permitted merely to enumerate a few of what I regard as the distinguishing features of 16th and 17th century scientific thought; however, let the conjectural character of what follows be quite clear: (1) Humanism, which encouraged the view that truth and nature value are to be identified with antiquity, led to the recovery of ancient philosophies like Pythagoreanism, atomism, and skepticism. (2) The skeptical crisis,  already discussed, cast doubt upon the possibility of  knowledge of the underlying causes. (3) A revival of  Pythagoreanism by Marsilio Ficino and others late in the 15th century led (among other things) to an  animistic natural philosophy and a stress on order and  of harmony. (4) The mechanical philosophy, based on the newly recovered works of the ancient atomists, was developed as a reaction against the animism of Renaissance Neo-Pythagoreanism as well as against  traditional Aristotelianism. (5) An Archimedean  approach to nature, introduced in the middle of the 16th century with the complete publication of Archimedes' works, stimulated the tendency to deal with nature mathematically. (6) A more critical spirit was fostered by the existence of competing natural philosophies and the skeptical crisis-though the absurdities of Cartesian physics should remind us to make no extreme claims in this direction. (7) Finally,  a larger population and greater affluence gave rise to a larger scientific community and more rapid progress, hereby exaggerating all other differences between the Middle Ages and the 16th and 17th centuries. It appears to me that most, if not all, other distinctive  features of 17th-century scientific thought are reducible to these.

number of recent authors (including David Siemens in the ASA journal) have argued that Christianity was one of the principal factors in the formu
lation of a new and viable science in the 16th and 17th
 centuries. This view of the relationship between Christianity and the progress of science springs from a misunderstanding of the scientific revolution of the 16th  and 17th centuries.


1The most vocal recent supporter of the "hedonist-liber tarian" view (and author of the phrase) is Lewis Feuer, The Scientific Intellectual (New York, 1963); among his fore runners he numbers such men as John W. Draper and Andrew
Dickson White. For a slashing attack on Feuer's book, see the review by Donald Fleming in Isis, vol. 56 (1965), pp. 369-70.

2"Cross, Constellation, and Crucible: Lutheran Astrology and Alchemy in the Age of the Reformation," Ambix, vol. 11 1963), p. 65.

3A Firm Foundation for Modern Science," Christianity Today (October 22, 1965), p. 13.

4"The Sources of Science," Journal of the American Scientific Affiliation, vol. 18 (1966), p. 85.

5"Science, Technology and Society in Seventeenth Century England," Osiris vol. 4 ( 1938), p. 453. For other literature expressing a similar view, see Robert K. Merton, "Puritanism, Pietism, and Science," The Sociological Review, voI. 28 (1936), pp. 1-30; Dorothy Stimson, "Puritanism and the New Philosophy in 17th Century England," Bulletin of the Institute of the History of Medicine, vol. 3 (1935), pp. 321-334; R. Hooykaas, "Science and Reformation," in The Evolution of Science, edd. Guy S. Metraux and Francois Crouzet (New York, 1963), pp. 258-290. See also the debate between Hugh F. Kearney and Christopher Hill in Past and Present, vols. 2832 (1964-65).

6Siernens, op. cit., p. 84. Note his abstract as well as his text.

7See, for example, Marshall Clagett, The Science of Mechanics in the Middle Ages (Madison, Wisconsin, 1959). A. C. Crombie (see n. 19, below) has also been a vocal spokesman for the continuity view, though be has overstated the case.

8The most useful book on Copernicus is undoubtedly Thomas S. Kuhn, The Copernican Revolution (Cambridge, Mass, 1957).

9See the Preface and Book I. The equant is a point other than the center of the orbit, with respect to which the angular motion of the planet is uniform. Copernicus' view is clearly revealed by the following quotation from his Commentariolus (1512): "Yet the planetary theories of Ptolemy and most other astronomers, although consistent with the numerical data, seemed likewise to present no small difficulty. For these theories were not adequate unless certain equants were also conceived; it then appeared that a planet moved with uniform velocity neither on its deferent nor about the center of its epicycle. Hence a system of this sort seemed neither sufficiently absolute nor sufficiently pleasing to the mind. Having become aware of these defects, I often considered whether there could perhaps be found a more reasonable arrangement of circles, from which every apparent inequality would be derived and in which everything would move uniformly about its proper center, as the rule of absolute motion requires." (Three Copernican Treatises, tr. Edward Rosen [New York, 19591.)

10The dissatisfaction at Cracow with Ptolemaic astronomy is illustrated by the Commentary on George Peurbach's New Theories of the Planets by Albert Brudzewski, Cracow's most noted astronomer in the 15th century.

11See Eugeniusz Rybka, Four Hundred Years of the Copernican Heritage (Cracow, 1964), chap. 7. On the Hermetic movement, of which Neo-Pythagoreanism was one facet, see Frances Yates, Giordano Bruno and the Hermetic Tradition (Chicago, 1964).

12Book 1, chap. 10. C. G. Wallis's translation of De revolutionibus in the Great Books series is exceedingly untrustworthy. A good translation of the Preface and Book 1, by John F. Dobson and Selig Brodetsky, appeared in the Occasional Notes of the Royal Astronomical Society, vol. 2, no. 10 (1947). Kuhn quotes extensively from this latter translation.

13Preface of De revolutionibus, Dobson and Brodetsky translation.

14Quoted by Thomas W. Africa, "Copernicus' Relation to Aristarchus and Pythagoras," Isis, vol. 52 (1961), p. 407.

151bid., p. 409.
16The mean-speed theorem asserts that the distance traversed by a body undergoing uniformly accelerated motion is the same as the distance traversed by another body moving for the same length of time at the mean speed of the first body. The odd-numbers law asserts that a body undergoing uniformly accelerated motion, beginning from rest, traverses three times as much space in the second unit of time as in the first unit of time, five times as much space in the third unit of time, and so forth; this is mathematically equivalent to Galileo's statement that s is proportional t2. Both conclusions were reached at Merton College, Oxford, by about 1330 and were widely known throughout the later Middle Ages; cf. Clagett, op. cit.

170n medieval mechanics in general, see Clagett, op. cit. An excellent study of Galileo and his relationship to the medieval mechanical tradition is Ernest A. Moody, "Galileo and Avempace: The Dynamics of the Leaning Tower Experiment," journal of the History of Ideas, vol. 12 (1951), pp. 163-193, 375-422.

Soto published his conclusions in his Super octo libros physicorum questiones (Salamanca, 1555). Traditionally it has been held that Galileo could have had no access to Soto's conclusions, but recently William A. Wallace, O.P., who has been investigating Soto's work, has called attention to the fact that the above work of Soto was published in Venice in 1582 and was circulating in northern Italy during Galileo's student days and, moreover, that Galileo mentions Soto's name in his student notebooks; cf. Wallace, "The 'Calculatores' in Early Sixteenth-Century Physics," unpublished paper.

In all fairness, I should point out that Galileo's work on projectile motion was more original than his work on falling bodies; nevertheless, even on this problem, Galileo was the culminating figure in a long medieval tradition.

18See, for example, my forthcoming article, "The Cause of Refraction in Medieval Optics," British Journal for the History of Science, vol. 4 (June, 1968).

19A. C. Crombie, Robert Grosseteste and the Origins at Experimental Science 1100-1700 (Oxford, 1953). John Herman Randall, Jr., The School of Padua and the Emergence of Modern Science (Padua, 1961). On Bacon's methodology, see also Paolo Rossi, Francis Bacon: from Magic to Science (Chicago, 1968).

20For example, see Roger Bacon, Opus maius, IV, dist. 1, chap. 3.

21Crombie, op. cit., p. 3. Even Crombie's most forceful critic, Alexandre Koyre, has conceded this much; cf. Koyre, "The Origins of Modern Science: A New Interpretation," Diogenes, vol. 16 (1956), P. 13. If Crombie overstates the case for continuity (Koyre's concession notwithstanding), it is an equal overstatement to argue that the 17th century was the scene of a revolution in methodology.

220n Ptolemy's optical work, see A. Lejeune, Euclide et Ptolemee (Louvain, 1948); Lejeune, Recherches sur la catoptrique grecque (Bruxelles, 1957). On Ibn al-Haitham (Alhazen), see Matthias Schramn, Ibn al-Haythams Weg zur Physik (Wiesbaden, 1963); cf. my "Alhazen's Theory of Vision and Its Reception in the West," Isis, vol. 58 (1967), pp. 321-341. On Theodoric, see William A. Wallace, O.P., The Scientific Methodology of Theodoric of Freiberg (Fribourg, Switzerland, 1959).

2317rom Galileo to Newton (London, 1963), p. 104.

240p. cit., p. 85.
25Letter to the Editor, Journal of the American Scientific Affiliation, vol. 19 (1967), pp. 125-126. If Aristotle was not seeking the rational order in the material universe, what was he doing? One might wish to argue that he did not find it, but surely not that he failed to search for it.

26The Mechanization of the World Picture, tr. C. Dikshoorn (Oxford, 1961), p. 72.

270n the aims of Baconian and Cartesian science, see the doctoral dissertation of ASA member Robert E. Snow, The Problem of Certainty: Bacon, Descartes, and Pascal. Indiana University, 1967.

280n the skeptical crisis, see Richard H. Popkin, The History of Skepticism from Erasmus to Descartes (New York, 1964).

29Physiologia Epicuro-Gassendo-Charltoniana: Or a Fabrick of Science Natural, upon the Hypothesis of Atoms (London, 1654), P. 127. As Peter A. Pav has pointed out ("Gassendi's Statement of the Principle of Inertia," Isis, vol. 57 (1966], p. 26), Charleton's work is frequently a literal rendition of Gassendi's Animadversiones (1649). 1 have modernized Charleton's orthography and punctuation.

3OCharleton, op. cit., p. 128~
32Dialogue Concerning the Two Chief World Systems, tr. Stillman Drake (Berkeley/Los Angeles, 1953), p. 234.

33Dialogue Concerning Two New Sciences, tr. Henry Crew and Alfonso de Salvio (New York, 1914), pp. 166-167.

34See Richard S. Westfall, "The Foundations of Newton's Philosophy of Nature," British Journal for the History of Science, vol. 1 (1962-63), pp. 171-182.

35Mathematical Principles of Natural Philosophy, tr. MotteCajori (Berkeley, Calif., 1960), p. 546.

361 am not here adopting a positivistic interpretation of Newton; Newton was indeed interested in the cause of
gravity, but he recognized the provisional nature of any such hypothesis, whereas he knew that certainty, could be obtained in a mathematical description of the phenomena. On Newton's attitude toward hypotheses, see Aexandre Koyre, Newtonian Studies (London, 1965).  Even Hooykaas, who would agree with Siemens' general point regarding the close relationship between the Reformation and the rise of science, recognizes the antirationalism pf 17th century scientific thought when he writes: " In their antirationalism the spirit of the Reformation and the spirit of experimental science show a close affinity." Hooykaas, op. cit., p. 267)