THOMISM AND MODERN SCIENCE:

RELATIONSHIPS PAST, PRESENT, AND FUTURE

William A. Wallace, O. P.

Dominican House of Studies

Washington, D. C.

THE IMPORTANCE of science and technology in the modern world is generally recognized by the Christian community. The Second Vatican Council, in fact, singled them out as dominant factors in our civilization, factors that are most responsible for the changing thought patterns of the twentieth century. The Council Fathers pointed to " the mathematical and natural sciences " as having a profound impact " in the cultural sphere and on modes of thought."¹ The life sciences and the social sciences, they acknowledged, are contributing also to the intellectual revolution that characterizes our age. Just as the Council of Trent over four centuries ago warned Catholics of theological innovations that could undermine their faith, so, in a more positive spirit, the Second Vatican Council directs attention to secular transformations to which the Church must adjust if she is to carry out her mission in the modern world.

As a consequence of the Council's teaching, those charged with fostering the intellectual life within the Church are encouraged to take a positive attitude toward scientific disciplines. And, since so much of the Church's intellectual life is associated with scholasticism, and with Thomism in particular, the opportunity is thereby provided to examine anew the relationships between Thomism and modern science. The aim of such an examination, of course, is to chart a program for the future. Such a charting presupposes a knowledge of the present situation, but even more it presupposes a correct understanding of what has happened in the past. Thomism has existed for close to seven hundred years, and modern science has a history of about half that span. If it is difficult to back

¹ The Pastoral Constitution, Gaudium et Spes, On the Church in the Modern World, Preface, No. 5.

off and study the present situation, it is relatively simple to view the past, to see there what has been good and what bad in the relationships between Thomism and science, and from this to make plans for the future.

The Medieval Past

The early history of this relationship, that before the rise of modern science in the early seventeenth century, does not require lengthy exposition. Because of the Aristotelian thought context in which medieval science was located, both St. Thomas and his teacher, St. Albert the Great, took an active interest in, and wrote competently on, topics that were to interest the precursors of modern science. For example, they discussed motion and the conceptual foundations of what was later to become the science of mechanics;² they evaluated the astronomical theories of their time;³ they had distinctive views on the structure of matter that went far beyond those of their contemporaries.⁴ Thomistic science, as practiced by St. Thomas and

² St. Albert, for example, is usually cited for his use of the terms fluxus formae and forma fluens to characterize the diverse ways of viewing the entitative status of motion in general, and of local motion in particular. This distinction, taken up in the fourteenth century by nominalists and realists, became a fruitful source of discussion from which the new science of mechanics, in both its kinematical and dynamical aspects, was to emerge. See Anneliese Maier, Die Vorläufer Galileis im 14. Jahrhundert (Roma: 1949), pp. 11-16. Similarly, St. Thomas is singled out for attention, because of his teaching, contrary to Aristotle and Averroes, that motion through a void would not be instantaneous, thus indirectly influencing the development of a concept of inertial resistance to motion among later thinkers such as Nicole Oresme. See A. Maier, Zwischen Philosophie und Mechanik (Roma: 1958), pp. 226, 246, 257, 266-279.

³ For St. Thomas's critical evaluation of medieval astronomical theories, see Thomas Litt, O.C.S.O., Les corps célestes dans l'univers de saint Thomas d'Aquin. Philosophes Médiévaux, Tome VII (Louvain/Paris: 1963); also W. A. Wallace, O. P., Cosmogony. Vol. X of St. Thomas Aquinas, Summa Theologiae (New York/London: 1967), English translation, with notes and appendices on Thomas's science.

⁴ St. Albert, with unusual foresight, endorsed the atoms of Democritus as providing an insight into the structure of material substance, provided they be interpreted as physical parts of bodies in the sense of minima naturalia. St. Thomas, in his turn, made a considerable advance beyond the teaching of Avicenna and Averroes with his theory of the virtual presence of elements in compounds. For details, see A. Maier, An der Grenze von Scholastik und Naturwissenchaft, 2. Auflage (Roma: 1952), pp. 31-38.

his early followers, was not divorced from philosophy and theology. It entered into the very fabric of the Thomistic synthesis and was responsible, in large part, for the value of that synthesis as an integration of all of knowledge, both human and divine.

Until very recently, little has been known about the role of Thomists and other scholastic thinkers in laying the foundations for modern science during the fourteenth, fifteenth, and sixteenth centuries. One of the pioneer historians of this period, Pierre Duhem, however, attempted some fifty years ago to verify the thesis that Leonardo da Vinci was the key figure in effecting the transition from scholastic patterns of thought to those of Galileo.⁵ Duhem's researches led him in an unexpected direction. Rather than confirming his conjecture about Leonardo da Vinci, they brought him to a hitherto unknown personality in the history of science, the Spanish Dominican and Thomist, Domingo de Soto.⁶ Duhem was able to point out that Soto had equivalently formulated what was later to become Galileo's law of falling bodies some eighty years before this was published by the great Italian physicist.⁷ In fact, since Soto's writings were known to Galileo in his youth, the Spanish Dominican may have had a direct influence on the evolution of the science of mechanics as it is now known.⁸

It is not necessary to verify such an influence, however, to

⁵ Etudes sur Léonard de Vinci. Ceux qu'il a lus et ceux qui l'ont lu. 3 Vols. (Paris: 1906-13).

⁶ Ibid., Vol. Ill, pp. 263-582, section entitled " Dominique Soto et la scolastique parisienne." For a critical study of Soto's life and works, see Vicente Beltran de Heredia, Domingo de Soto. Estudio Biográfico Documentado. (Salamanca: 1960).

⁷ For verification of Duhem's thesis in considerable detail see my article entitled " The Enigma of Domingo de Soto: Uniformiter Diformis and Falling Bodies in Late Medieval Physics," to be published in Isis.

⁸ An edition of Soto's Quaestiones super octo libros Physicorum, Aristotelis, which contains the discovery relating to falling bodies, was published at Venice in 1582 and dedicated to the Italian Dominican, Domenico Bolano. Galileo studied at Pisa and Padua shortly after this date, and, in his Juvenilia (commonly regarded as his student notebooks), makes reference to one of Soto's Quaestiones, thereby indicating
that these were available either to himself or to his teachers.

show that the Thomists of the fifteenth and sixteenth centuries were actively interested in the velocities of falling bodies, projectiles, motion in a vacuum, and similar problems whose discussion led to the new science of mechanics. Their various opuscula, as well as their commentaries and " questionaries " on the Physics of Aristotle,⁹ show them taking part in the controversies between the nominalists and the realists that were so important for this development.¹⁰ They knew the science and the mathematics of their day, and they contributed intelligently to its development, as well as to its integration within the broader framework of their philosophy and theology.

The Modern Past

By the end of the sixteenth century, however, a changed attitude on the part of Thomistic writers becomes detectable. The change, unfortunately, was to the detriment of scientific and mathematical interests, although it seems to have come about without any prejudice against these disciplines. The fact that most Dominicans in this period seem to have been engaged in teaching seminarians goes far to explain what happened. Few, if any, were professionally interested in science. Faced with a pedagogical problem of communicating the more metaphysical theses that are necessary for sacred theology, and possibly teaching students who had insufficient knowledge of

⁹ Among the works of Dominicans, apart from Soto, who discussed topics relating to physics or astronomy, we may mention: Giovanni Graziadei (di Ascoli), Quaestiones in libros Physicorum Aristotelis (Venice: 1484); Crisostomo Javelli, In libros Physicorum Quaestiones (Lyons: 1568); Isidore Isolano, De velocitate motuum (Pavia: 1522); Petrus Crokart de Bruxellis, Argutissime, subtiles et fecundi Questiones physicales . . . (Paris: 1521); Amadeus Meygretus, Questiones in libros De Celo et Mundo Aristotelis . . . (Paris: 1514); Diego de Astudillo, Quaestiones super octo libros Physicorum et super duos libros De Generatione Aristotelis . . . (Valladolid: 1532); and Domingo Báñez, Commentaria et Quaestiones in duos De Generatione et Corruptione libros (Salamanca: 1585).

¹⁰ Soto, in fact, attempted to show how the nominalists and the realists both " sin through excess " in discussing such matters as the entitative status of local motion. For a brief statement of his resolution, see my paper, " The Concept of Motion in the Sixteenth Century," to be published in the Proceedings of the American Catholic Philosophical Association for 1967.

mathematics, they gradually abandoned the tradition in which technical problems relating to Aristotle's Physics were given full treatment. Instead, they began what was to become known as the " manual tradition " in scholastic philosophy. In place of questions on the velocities of motion, for example, they introduced sections on creation, subsistence, and problems related to the Eucharist into natural philosophy.¹¹ By the time Galileo and Newton were writing the revolutionary treatises that would shape modern thought for the next three centuries, such treatises were no longer of immediate interest to Thomists. Entering, then, on the second phase of the history of the relationships between Thomism and modern science, a phase in which science has already emerged in its present-day form and in which Thomism has already taken on the characteristics of a system (and a closed system at that), one can only be disappointed with what is seen. In the post-Tridentine period, the teaching Church had already assumed an authoritarian air that extended to all areas of knowledge, modern science included. At the same time, those who were charged with advancing the intellectual life within the Church, who might have been expected to benefit from contact with the new disciplines, were not themselves prepared to read and evaluate critically the works in which they were contained. As a consequence, the scene was set for a disastrous encounter between

¹¹ This is particularly noticeable when one traces the development of the textbooks of the Spanish Thomists who came after Soto, viz., Diego Mas, O. P., Commentaria in universam philosophiam Aristotelis una cum quaestionibus quae a gravissimis viris disputari solent. (Valencia: 1599); Juan Martínez de Prado, O.P.. Quaestiones philosophiae naturalis in tres partes distributae. (Alcalá: 1651-52); Cosme de Lerma, O. P., Commentaria in octo libros Physicorum, ed. 2a (Burgos: 1655); Diego Ortiz, O. P., Philosophiae brevis explicatio, cum gravioribus questionibus a philosophis disputari solitis (Seville: 1678); and Frolán Díaz, O. P., Philosophia naturalis per questiones et articulos divisa iuxta mentem D. Thomae (Valladolid: 1695). Many, such as Lerma and Ortiz, believed that they were following Soto's doctrines, although actually they departed from him, particularly in their metaphysical emphases. For a sketch of the more favorable aspects of this development, see Santiago Ramírez, O. P., " Hacia una renovación de nuestros estudios filosóficos. (Un indice de la producción filosófica de los Dominicos españoles)." Estudios Filosóficos, I (1952), pp. 3-23.

Thomism and modern science that has had unfortunate consequences, reaching all the way to the present day.

One aspect of this confrontation, valuable for the lesson it affords, may be examined in the impact on Thomistic manuals of natural philosophy of the two most important works in the history of mechanics and astronomy, Galileo's Dialogues Concerning Two New Sciences (1638) and Newton's Mathematical Principles of Natural Philosophy (1687; 2nd edition 1713). Since this examination, by reason of space, cannot be exhaustive, it will concentrate on three of the most representative manuals in the period from the end of the seventeenth to the end of the nineteenth century, namely, those of Goudin, Roselli, and Lepidi.

Antoine Goudin's Philosophia iuxta inconcussa tutissimaque D. Thomae dogmata first appeared in 1671 and went through many revisions and editions to the end of the nineteenth century.¹² The edition of 1726 is of interest for its treatment of the laws of motion.¹³ Goudin exposes the traditional teaching of Aristotle and St. Thomas, but nowhere mentions the works of Galileo or of Newton. He does have a section on the laws of motion and impetus, which is devoted exclusively, however, to a consideration of laws proposed by Descartes. In fact, one would gain the impression that Descartes alone had made innovations in the science of mechanics, so extensive are Goudin's references to the French thinker.¹⁴ Goudin still speaks of heavy and light bodies, apparently not having learned from Galileo that this distinction was no longer viable;¹⁵ he mentions

¹² For details of Goudin's life and writings, see J. Quétif, O. P., and J. Échard, O. P., Scriptores Ordinis Praedicatorum (Paris: 1721), Tom. II, p. 740.

¹³ Volume 2 of the Cologne 1726 edition is devoted to the first part of the Physics, dealing with ens mobile in communi. The third disputation, which treats of motion as a property of changeable being, has a section entitled " De legibus motus et impetus localis," pp. 280-282.

¹⁴ This seems to be characteristic of the Thomistic manualists of the period; they generally concentrated on Descartes and such thinkers as Mersenne, Maignan, and Gassendi, and paid little attention to the more mathematical treatises of writers like Galileo and Newton.

¹⁵ Galileo's teacher, G. B. Benedetti, had already rejected the existence of levity (levitas), maintaining that all bodies in the universe are heavy, and Galileo followed him in this. The first convincing proof, however, came from Newton, with the evidence he adduced for the law of universal gravitation. Goudin mentions none of these thinkers, restricting his attention to Descartes and Gassendi; his own opinion is expressed in the words, " itaque dico, sicut corpus grave innato impetu tendit deorsum, ita leve sursum " (op. cit., p. 256).

Galileo, along with William Gilbert, in discussing magnetism;¹⁶ and he grants that the acceleration of falling objects is proportional to the series of odd numbers,¹⁷ but disclaims any intention of going into details on such matters. There is not even a mention of Newton in the section on laws of motion, even though the Principia had appeared almost forty years before. In an 1854 edition,¹⁸ Newton's laws are discussed in an extended footnote, where they are pointed out as being completely false; the footnote is undoubtedly the work of an editor,¹⁹ however, and seems to have been borrowed from another manualist, viz., Roselli.

The Summa Philosophica of Salvator Maria Roselli is a monumental treatise in that it not only attempts to expose Thomistic thought thoroughly, but also tries to take account of innovations among the moderns.²⁰ Roselli devotes considerable attention to Newton and his commentators and is willing to accord to Newton's synthesis some mathematical validity, although in general he is opposed to all of its physical doctrines.

¹⁸ " Quantum ad res quibus ea vis [scil., vis magnetica] inest, primo ac praecipue interioribus terreni globi partibus ac eius veluti nucleo inesse docent, qui de vi magnetica diligentius scripsere, Gilbertus, Galilaeus, Cartesius et alii" ibid., p. 267.

¹⁷ " Porro qua proportioue acceleretur motus gravium, viri solertes cum variis experimentis quaesiverint, reperiere accelerari juxta progressum numerorum imparium . . ." ibid., p. 280. This teaching is contained in Galileo's Dialogues Concerning Two New Sciences; it was known from the fourteenth century onward, however, that this mathematical relationship is verified in all uniformly accelerated motions.

¹⁸ Both this edition and that of 1726 are cited because they are the only early editions of Goudin available to me.

¹⁹ Goudin himself died on October 25, 1695; the tenth edition of the work, the last under his care, appeared in 1692. See Quétif-Échard, op. cit., Vol. II, p. 740.

²⁰ For a full description of this work and the background against which it was written, see E. I. Narciso, O. P., La Summa Philosophica di Salvatore Roselli e la Rinascità del Tomismo. Studi e Ricerche sulla Rinascità del Tomismo, n. 2 (Roma: 1966). References to Roselli that appear below are from the Madrid edition of 1788.

Roselli denies the existence of universal attraction, however this is to be understood, and holds that the element fire is absolutely light.²¹ The heavenly bodies, in his estimation, are neither heavy nor light, because he still is convinced that they move in circular paths according to Aristotelian teaching.²² He examines with some care Newton's laws of motion, but finds all of them false, and substitutes in their place his own laws of motion.²³ These, unfortunately, miss the point behind Newton's " mathematical principles of natural philosophy," and are sterile for providing any insight into the structure of the system of the world. Considering that Roselli prepared his second edition almost a hundred years after Newton's classic,²⁴ this failure to grasp the physical import of Newton's reasoning is almost incomprehensible.²⁵

When Roselli comes to discuss the system of the world, moreover, there can be no doubt that he is still defending a geocentric universe. He rejects the Ptolemaic system, and also that of Tycho Brahe, on the grounds that the physical principles on which they are based are false.²⁶ He is willing to admit the Copernican system as a hypothesis, but teaches that it can be in no way defended when holding that the sun is at rest and that the earth moves.²⁷ Discussing the cause of the

²¹ Summa philosophica, Vol. II, pp. 361-372.

²² Ibid., pp. 455-466.

²³ Ibid., pp. 455-466.

²⁴ The first edition of the Summa philosophica appeared in 1777, and the second edition in 1783. A third edition was printed at Bologna between 1857 and 1859; this was requested by the 1838 General Chapter of the Dominicans, with the proviso that the parts dealing with physics be reduced; to a few questions.

²⁵ As Newton himself maintained, he attempted to argue from the properties of celestial motion that can be analyzed mathematically to a knowledge of the physical cause of such motion, and thus reasoned to the presence of gravity in all bodies of the solar system whose motions were observable. He disclaimed any knowledge of the cause of gravity, and did not wish to frame any hypotheses (hypotheses non fingo) on this subject, since it was not directly related to his argument. Once he had proved a posteriori that celestial bodies obey the law of gravitation, he could argue forcefully for the heliocentric system on the basis of physical principles, and not as a mere mathematical hypothesis.

²⁶ Summa philosophica, Vol. Ill, pp. 172-203.

²⁷ Ibid., pp. 204-207.

motion of the stars, Roselli rejects Kepler's thesis, together with the systems of Descartes and Leibniz.²⁸ He also examines and rejects Newton's analysis of the system of the world, and concludes with his own thesis, namely, that the heavenly bodies have no active principle of motion within them, that they are not moved directly by God, but that they are moved by the angels.³⁰

Roselli's manual had a great influence on the subsequent development of scholasticism. Not only was some of his material excerpted and inserted in subsequent editions of other manuals, such as Goudin's, but as late as 1875 a five-volume Institutiones Philosophicae ad mentem angelici Doctoris S. Thomae Aquinatis ordinatae was issued at the Abbey of Monte Casino containing substantially all his teachings, including his evaluations of Newton's mechanics.³¹ Although the Dominicans had rejected this part of Roselli's manual as early as 1838,³² this shows that teachers who regarded themselves as authentic Thomists were still using Roselli's analyses almost two hundred years after the first appearance of Newton's Principia.

Of less interest and importance is the treatment of Alberto Lepidi in his Elementa philosophiae christianae, published at

²⁸ Ibid., pp. 402-426.

²⁹ Ibid., pp. 426-445.

³⁰ Ibid., pp. 445-452. This seems to reveal a misunderstanding, on Roselli's part, of the orders of causality involved. There would seem to be no repugnance in allowing for gravity as a passive principle of motion within the heavenly body, as St. Thomas taught was the case for earthly bodies, and at the same time allowing for immaterial movers (such as angels) as active principles of the motion.

³¹ The author (anonymous) evidently compiled this text from other works, as he himself states in the introduction to Vol. II: " Institutiones physicas ita concinnare curabimus, materiam a probatissimis Auctoribus sive antiquis, sive recentioribus excerpendo, quae magis scitu necessaria viris ecclesiasticis videtur. Quaedam enim res, licet physicae sint, sacrae tamen doctrinae inserviunt, quas diligenter persequitur P. Salvator Maria Roselli, O. P., ideoque eius opere praecipue utemur" (p. 2). The writer's analysis of the forces involved in maintaining equilibrium in the solar system, however, reveals a complete misunderstanding of Newtonian mechanics (pp. 233-234).

³² See E. I. Narciso, op. cit., p. 139, fn. 13.

Paris and Louvain in 1879.³³ Discussing the properties of corporeal substance, Lepidi treats of the concept of inertia, which he acknowledges as deriving from the " Principles of Philosophy" of Sir Isaac Newton.³⁴ By this time, Thomists seem willing to concede that there is possibly some truth in Newton's teaching. Lepidi, at any rate, shows himself an opportunist in wishing to use the Newtonian concept of inertia for arguing against materialists.³⁵ He accepts inertia as a fact, although he does not think its nature is correctly understood by the moderns, and regards it as a conclusive proof that the motion or rest of any physical body can only be explained by some external cause.³⁶

Other cases could be adduced, but these are sufficient to characterize the attitude of Thomists toward Newtonian science during the period when the thought of Newton had already gained acceptance in the great university centers of western Europe and in the U. S.³⁷ In all fairness to the Dominicans we have mentioned, they were not completely arbitrary in their rejection of certain aspects of Newton's teaching. As only recent work in the philosophy of science has shown, Newton's laws of motion are not without their logical and their extra-logical difficulties.³⁸ It is to the credit

³³ Lepidi was born on February 20, 1839, and died on July 31, 1925. His Cosmologia was the third and last volume of his Elementa philosophiae christianae; the first volume of the series appeared in 1875.

³⁴ Vol. Ill, pp. 143-145. The title, Principia philosophiae, actually refers to the work of Descartes, not Newton; some editions of Newton's classic, however, were printed with these words of the title in bold type, e. g., principia mathematica philosophiae naturalis, thus suggesting an affinity to the title of Descartes' work.

³⁵ Ibid., p. 144.

³⁶ Ibid., p. 145.

³⁷ Perhaps this unsympathetic treatment of Newton is explainable by the fact that most scholastic manualists were of Italian, Spanish, and French nationality. Their knowledge of Newton seems to have been gleaned from the writings of French partisans of Descartes and Leibniz, who were themselves strongly anti-Newtonian. The manualists, of course, rejected both Descartes and Leibniz, and, along with them, Newton as representing a more extreme position to which even they were opposed.

³⁸ For a contemporary evaluation of these difficulties, see W. A. Wallace, O. P., " Newtonian Antinomies Against the Prima Via," The Thomist 19 (1956), pp. 151-192. Others outside the scholastic tradition have made similar criticisms, e. g., Ernest Nagel, The Structure of Science. Problems in the Logic of Scientific Explanation. (New York: 1961), pp. 153-202.

of these Thomists that they were more alert than many of their contemporaries in detecting flaws in Newtonian reasoning. At the same time, however, one should not overlook the fact that their attitude toward the science of mechanics, and the new astronomy, was essentially negative. They were convinced, to a man, that they already possessed the whole truth about the structure of the universe, and their minds were not open to the possibility of any new knowledge coming from modern science.

To recapitulate, then, the history of the relationships between Thomism and modern science is partly good and partly bad. From the time of St. Thomas all the way to the sixteenth century, there is a sincere interest in science and its problems, and a definite contribution is made to its progress. From the beginning of the seventeenth century to the end of the nineteenth, however, the attitude is reversed. Thomists subordinate all of their philosophical teachings to theology; they are already convinced that they possess the absolute truth and they attack any new proposal as undermining the very foundations of the Catholic faith. Finally, by the end of the nineteenth century, they grow increasingly aware that much of their rejection of modern science is arbitrary, and gradually they delete all references to science from their manuals of philosophy. They make a hurried retreat from natural philosophy, and place emphasis instead on metaphysics. Thus begins Thomism's uneasy rapprochement with contemporary thought: Thomistic cosmology, now recognized as " without a cosmos," is restricted to a few generalities, and Thomism itself is seen as a magnificent synthesis, erected on simple sense observation alone, and standing in complete independence of modern science.

The Present

This brings up the present situation, where science has become one of the most influential factors in contemporary

civilization. While no longer attacked from without, or at least not with the vehemence of the previous centuries, science now has problems that have arisen largely within itself. Some of these are associated with the extremely rapid growth of scientific activity during the twentieth century; others come from a concern over the very foundations of science and mathematics themselves, occasioned by new theories such as relativity and quantum theory, that cast doubt on the Newtonian world view so long accepted by the scientific community.

An example of the first type of difficulty is the present " information explosion." The methods in which Galileo and Newton pioneered have been brought to fruition in the early part of this century, and science, particularly in the U. S., has become a " big business." Vast amounts of money, from government and private sources, are poured annually into all types of research activity. Data are accumulated at a much faster rate than human beings can organize and assimilate them. Lagging only slightly behind this accumulation of data is a rapid proliferation of theories,, which themselves require evaluation. Scientists now have so much information they do not know what to do with it. The pressing problem, felt everywhere, is a lack of integration in knowledge, and this not only within science--for the physicist can no longer speak with the chemist or the biologist on the details of his science, and even finds few physicists with whom he can converse over his specialty--but also in science's relation to other disciplines. The problem of the " two cultures," so much discussed in Britain and the U. S., is symptomatic of the lack of integration in all areas of knowledge.³⁹

Examples of the second type of difficulty besetting scientists are provided by the relativity theory, with its concern over the structure of the very large, and the quantum theory, at the other extreme, with its concern over the structure of the very small. Both of these theories raise perplexing problems of

³⁹ Attention was focused on this problem by the work of C. P. Snow, The Two Cultures and the Scientific Revolution (New York: 1961).

interpretation that have caused scientists, at least, to seek help from philosophers in an attempt to extricate themselves from their own antinomies. In fact, as a result of this type of problem arising within science, there has been a growth of disciplines that are closely related to science and its problems, such as the history of science, the philosophy of science, the sociology of science, etc.

Disciplines such as these offer some promise of bridging the gap that has been developing between the " two cultures," and also of offering help in coping with the " information explosion." Quite unexpectedly, they also offer some promise for a renewal of cooperation between Thomism and modern science. Those scientists, for example, who/ have been studying the historical foundations of their disciplines, in their attempts to understand the intellectual milieu in which science originated, have become more open to philosophies other than mechanism and positivism, which so long dominated their thinking. The great interest in the medieval precursors of Galileo has led some to reexamine the conflicts between the nominalists and the realists, and to see advantages in Thomism that have generally been overlooked by secular scholars. Even the criticisms of Cartesian and Newtonian thought mentioned in the early part of this study can now be examined impartially, and there is a growing recognition that the failure of Thomists to go along with an accepted Newtonian world view in the seventeenth to the nineteenth centuries was not simply a matter of religious prejudice. There was also a valid philosophical content to their critique, from which scientists themselves could have learned, had they too been patient with those who were apparently their adversaries.

Similarly, the study of the philosophy of science, particularly as practiced in the U. S., has produced an atmosphere in which a Thomistic philosopher once again is able to breathe. It is true that the origins of the philosophy-of-science movement in the Vienna Circle showed a remarkably positivist and empiricist bias. Many members of the Vienna Circle emigrated to the United States, where they contributed heavily to the growth

of logical positivism as a prevailing philosophy in American universities. Within the past decade, however, there has been a disenchantment with the type of philosophy of science proposed by logical positivists, and this on the part of scientists themselves. There is increasing awareness that the methods actually used by practicing scientists have little or nothing to do with the complex formalistic analyses of logical positivism. In reaction, there has been a gradual shift toward realism on the part of scientists generally, and of a few influential philosophers of science in particular.⁴⁰ The brand of realism that is presently favored is materialistic and ultra-realist, by Thomistic standards, but it nonetheless introduces a polarization within the philosophy of science that can make Thomism of interest to practitioners of this discipline. The situation is analogous to the one that prevailed from the fourteenth to the sixteenth centuries, when nominalism and realism were in direct opposition, and Thomism could appear as a " middle of the road " philosophy capable of assimilating the values in both extremes.⁴¹

Thus it is that the growth of the history and philosophy of science offers promise for a rapprochement between Thomism and the scientific culture of the late twentieth century. Apart from this, there is cause for optimism when Thomism is considered vis-à-vis the " information explosion " and the integration of knowledge required in the present day. Thomism is sufficiently analytical to be acceptable to the scientific mind. Apart from providing an analysis, however, it is also a synthesis, and one that is capable of tying together the most diverse strands of knowledge in a meaningful way. Its basic insights into the structure of matter, into the living organism.

⁴⁰ Among these philosophers of science may be enumerated David Bohm, Mario Bunge, P. K. Feyerabend, and R. S. Cohen, some of whom are Marxist in their philosophical sympathies.

⁴¹ See fn. 10 above. There are marked affinities between sixteenth-century nominalism and realism and twentieth-century neo-empiricism and materialism as diametrically opposed philosophical viewpoints; Thomists, as moderate realists, recognize all four as extreme positions.

into man and society, etc., provide a broad foundation on which rapidly multiplying scientific disciplines may find a unified intelligibility.

This new relevance of Thomism to twentieth-century culture carries with it an important message for Catholic philosophers and theologians in the aftermath of the Second Vatican Council. To some extent in Western Europe, and to a lesser extent in the U. S., Catholic philosophers have been cultivating personalist, existentialist, and phenomenological philosophies as one way of updating Catholic thought and making it more relevant to the concerns of man and society. Such philosophies are not without their value, but for the most part they are incapable of dealing with modern science and its problems. Catholics understandably feel at home with them because they speak about person, and existence, and the transcendent concerns that have been always those of Christianity. But the more Catholic thinkers endorse existentialism, phenomenology, and personalism, and the more they divorce themselves from the hard thinking that characterizes a scientific culture, the more divisive they become, and as a consequence the less they do to promote the integration of knowledge. At the worst, they openly combat the modern scientist, and at the best, they patronizingly attempt to supplement what he is saying, while speaking in a language that is utterly different from his own. The end result can only be an alienation from Catholic thought of a major component of twentieth-century culture, a component that the Second Vatican Council was most concerned not to alienate.⁴²

Thomism, on the other hand, is an open-ended synthesis that is capable of assimilating the good to be found in modern science and its methods, as well as the good to be found in existentialism, phenomenology, and personalism. As such it offers the greatest hope for solving the problems of modern

⁴² Father Ernan McMullin, in his Presidential Address to the American Catholic Philosophical Association at Notre Dame, Indiana, on March 28, 1967, forcefully called attention to other harmful consequences, in the U. S., of this general situation. The address is to be printed in the Proceedings for 1967.

man, for unifying all areas of knowledge, and for revitalizing Catholic thought along the lines suggested by the Second Vatican Council.

The Future

Thus a final concern suggests itself, viz., the relationship between Thomism and modern science that should be the goal of efforts in the future. Here one can be very brief. All that need be done is to avoid the mistakes of the past and apply well the lessons learned from history. What are the mistakes of the past? First, the long time period required for the assimilation of new knowledge, particularly when this involved a revolutionary viewpoint. As has been seen, it took from one to two hundred years before Thomists assimilated the essential content of Newtonian physics, and realized to what extent it applies to the physical universe. The point is not being made that Newtonian physics was true and accurate in all its specific details. Whether Newton and his followers were right or wrong is not at issue here; the simple fact is that far too long a time elapsed before their arguments were being evaluated constructively by scholastic thinkers generally, and by Thomists in particular.

Second, a point closely related to the first, the past history of Thomism has witnessed too facile a rejection of the good with the bad. The general principles that form the backbone of the Thomistic synthesis provide powerful standards against which to verify a new proposal; in the past, however, on the basis of these principles alone, Thomists have been too quick to reject an entire system immediately, without bothering to look at the good points it might contain. This has impeded the growth of Thomism, and particularly its assimilation of data from the positive sciences.

Third, a point not unrelated to the first and the second, in the past there has been too strong a commitment to authority (whether of St. Thomas or of the Church in endorsing him), and, as a consequence, a rigid adherence to prevailing views in all areas of thought. Thomists, in principle, state that

one should not rest on authority in matters philosophical, and yet de facto they have been doing precisely this.

Fourth, and this is particularly true of the latter period in Thomism's history, Thomists have been content to remain at a very general level, concentrating on metaphysics, and neglecting the specialized disciplines that have developed because of the needs of modern man. Without intending to do so, they have promoted a divorce between philosophy and science, and as a result, they have allowed their theology to be completely untouched by scientific progress.

One usually benefits from the mistakes of the past by conscientiously attempting to avoid them in the future. A simple way of doing this, and a most important way at that, is to return to a concept of the relationship between Thomism and science that existed at the time of St. Albert and St. Thomas. The pragmatic program of confining Thomism to a simplistic system of thought well adapted to the education of seminarians must be relinquished as quickly as possible. Instead, Thomists must be encouraged to become increasingly concerned with, and enlivened from, their contact with, the specific problems of the physical, biological, psychological, social and political sciences. Such a renewal will benefit not only Thomism but also the sciences it can serve to integrate. In so doing it will meet the needs of modern man and his society so strikingly pointed out by the Second Vatican Council.