The Philosophy of Nature and Natural Science from a Thomist Viewpoint

THE PHILOSOPHY OF NATURE AND NATURAL SCIENCE FROM A THOMIST VIEWPOINT T HE title of this study contains three terms which require some clarification: "philosophy of nature," "natural science," and " Thomist." The first two, of course, cannot be very much clarified at this point, since it is the purpose of the entire article to discuss their distinction one from the other. We ought, however, to begin with some kind of nominal definitions to indicate where the regions in question are to be found on the general map of knowledge. We might start by saying that the philosophy of nature is that knowledge of the physical universe which is sought by philosophers, while natural science is that kind of knowledge of the same physical universe which is sought by scientists. This scarcely seems sufficient, even as a merely nominal definition; but it is difficult to say more without immediately launching into the main theme. So we shall go on to our third term-" Thomist." What makes one a Thomist could quite well be the subject of another article, or perhaps a book. But briefly, to me a Thomist in the philosophy of nature is one who has adopted St. Thomas' philosophical perspective of matter and form, together with his general view of order and difference in knowledge based on differences in what is known, on levels of intelligibility and differences within those levels within the object itself, or what is saying the same, within being itself. This study is an attempt to use these Thomistic notions in order to see some distinctions and relations between the philosophy of nature and the natural sciences. Conspicuous by their absence, however, will be the usual collections of textual references to St. Thomas; for this is written from a Thomist viewpoint and not from that of St. 880 PHILOSOPHY OF NATUim AND NATURAL SCIENCE :~31 Thomas himself, who did not, it seems to me, have a fair chance to express himself completely on a problem which was not properly clarified until hundreds of years after his death. I. ANCIENT VIEWPOINTS AND THOMIST CouNTERPARTs The question of the precise relationship between the philosophy of nature and the natural sciences is the subject of much discussion among Thomist philosophers at the moment. This question has been with us ever since the clear distinction (at least de facto) between philosophy and the natural sciences began to emerge. Just when this distinction first appeared cannot be ascertained with certitude, although we have the testimony of Simplicius to the effect that Plato posed the problem of "saving" the astronomical phenomena to Eudoxus.1 The process of differentiation has been extremely graduaL It began to appear in Aristotle as an already accomplished fact in at least one realm-that of astronomy.2 The problem of the relationship of astronomy and philosophy is discussed in some detail by Geminus, a peripatetic of the first half of the first century B. C., in a text which has been transmitted to us by Simplicius.3 In this text, Geminus states that the astronomer accepts physical principles from the philosopher of nature at the outset of his science and goes on from there. This view, extended to take in not only astronomy but the other natural sciences as well, has had a rebirth in recent years among Thomists, and is held in one form or another by quite a number of present-day Aristotelians who are Thomists. In this group there is a general tendency to deny the autonomy of the natural sciences and to assimilate them to the philosophy 1 Simplicii in Aristotelis De Caelo Cmnmentaria, edidit J. L. Heiberg, Commentaria in Aristotelem Graeca, v. 7 (Berolini, 1894), p. 488 (II, 12, £19a 37-44). • Beta De Caelo, 10, 29la 29-32; 11, 291b 21-22; Lambda Metaphysicorum, 8, 1074a 14-17. • Simplicii in ATisiot. phys., eel. Dieh Co·rnmentaria in Aristotelem Graeca, v. 9, p. 291, I. 23-p. 292, I. 29. 332 JOSEPH J. SIKORA of nature (and to deny them the status of science insofar as they are not thus assimilated) . The common denominator of the groups seems to be the ideal of a single science of nature in which the...