ARISTOTLE ARISTOTLE bat-do di scienee e lettere, 18 (1898), fasc. 5 : and William not founded until after his death . But with some H. Stahl, "The Greek Heliocentric Theory and Its Abandon- distinguished students and associates he collected a ment," in Transactions of the American Philological Asso- natural history museum and a library of maps and ciation, 77 (1945), 321-332 . manuscripts (including his own essays and lecture WILLIAM H . STAHL notes), and organized a program of research which inter alia laid the foundation for all histories of Greek natural philosophy (see Theophrastus), mathematics ARISTOTLE (b. Stagira in Chalcidice, 384 B.C. ; d. and astronomy (see Eudemus), and medicine. Chalcis, 322 B.C.), the most influential ancient exponent Recent discussion of his intellectual development of the methodology and division of sciences; contributed has dwelt on the problem of distributing his works to physics, physical astronomy, meteorology, psy- between and within the three periods of his career . chology, biology. The following article is in four parts : But part of the stimulus to this inquiry was the Method, Physics, and Cosmology ; Natural History supposed success with which Plato's dialogues had and Zoology ; Anatomy and Physiology : Tradition been put in chronological order, and the analogy with and Influence . Plato is misleading . Everything that Aristotle polished Method, Physics, and Cosmology . for public reading in Plato's fashion has been lost, Aristotle's father served as personal physician save for fragments and later reports . The writings that to Amyntas II of Macedon, grandfather of Alexander survive are a collection edited in the first century B .C . the Great . Aristotle's interest in biology and in the (see below, Aristotle : Tradition), allegedly from manu- use of dissection is sometimes traced to his father's scripts long mislaid : a few items are spurious (among profession, but any suggestion of a rigorous family the scientific works Mechanica, Problemata, De training in medicine can be discounted . Both parents mundo, De plantis), most are working documents died while Aristotle was a boy, and his knowledge produced in the course of Aristotle's teaching and of human anatomy and physiology remained a nota- research ; and the notes and essays composing them bly weak spot in his biology . In 367, about the time have been arranged and amended not only by their of his seventeenth birthday, he came to Athens and author but also by his ancient editors and interpreters . became a member of Plato's Academy . Henceforth Sometimes an editorial title covers a batch of writings his career falls naturally into three periods . He re- on connected topics of which some seem to supersede mained with the Academy for twenty years . Then, others (thus Physics VII seems an unfinished attempt when Plato died in 347, he left the city and stayed at the argument for a prime mover which is carried away for twelve years: his reason for going may have out independently in Physics VIII) ; sometimes the been professional, a dislike of philosophical tenden- title represents an open file, a text annotated with cies represented in the Academy by Plato's nephew unabsorbed objections (e.g., the Topics) or with later and successor, Speusippus, but more probably it was and even post-Aristotelian observations (e .g., the His- political, the new anti-Macedonian mood of the city . toria anirnalium) . On the other hand it cannot be He returned in 335 when Athens had come under assumed that inconsistencies are always chronological Macedonian rule, and had twelve more years of pointers . In De caelo 1-II he argues for a fifth element teaching and research there . This third period ended in addition to the traditional four (fire, air, water, with the death of his pupil, Alexander the Great earth) : unlike them, its natural motion is circular and (323), and the revival of Macedon's enemies . Aristotle it forms the divine and unchanging substance of the was faced with a charge of impiety and went again heavenly bodies . Yet in De caelo III-IV . as in the into voluntary exile . A few months later he died on Physics, he discusses the elements without seeming his maternal estate in Chalcis . to provide for any such fifth body, and these writings His middle years away from Athens took him first are accordingly sometimes thought to be earlier. But to a court on the far side of the Aegean whose ruler, on another view of his methods (see below, on Hermeias, became his father-in-law ; then (344) to the dialectic) it becomes more intelligible that he should neighboring island Lesbos, probably at the suggestion try different and even discrepant approaches to a of Theophrastus, a native of the island and henceforth topic at the same time . a lifelong colleague : finally (342) back to Macedon Such considerations do not make it impossible to as tutor of the young prince Alexander . After his reconstruct something of the course of his scientific return to Athens he lectured chiefly in the grounds thinking from the extant writings, together with what of the Lyceum, a Gymnasium already popular with is known of his life . For instance it is sometimes said sophists and teachers. The Peripatetic school, as an that his distinction between "essence" and "accident," institution comparable to the Academy, was probably or between defining and nondefining characteristics, 25 0 ARISTOTLE ARISTOTLE must be rooted in the biological studies in which it on this as the chief aim of any science : it must not plays an integral part . But the distinction is explored merely record but explain, and in explaining it must, at greatest length in the Topics, a handbook of dia- so far as the special field of inquiry allows, generalize . lectical debate which dates substantially from his Thus mathematical proof becomes Aristotle's first earlier years in the Academy, whereas the inquiries paradigm of scientific explanation ; by contrast, the embodied in his biological works seem to come chiefly dialectic that Plato ranked higher the logical but from his years abroad, since they refer relatively often free-ranging analysis of the beliefs and usage of "the to the Asiatic coast and Lesbos and seldom to many and the wise"-is allowed only to help in southern Greece . So this piece of conceptual appa- settling those basic principles of a science that cannot, ratus was not produced by the work in biology . On without regress or circularity, be proved within the the contrary, it was modified by that work : when science itself. At any rate, this was the theory. Aristotle tries to reduce the definition of a species to Aristotle duly adapts and enlarges the mathe- one distinguishing mark (e .g., Metaphysics VII 12, matical model to provide for the physical sciences . VIII 6) he is a dialectician, facing a problem whose Mathematics, he holds, is itself a science (or rather ancestry includes Plato's theory of Forms, but when a family of sciences) about the physical world, and he rejects such definitions in favor of a cluster of not about a Platonic world of transcendent objects ; differentiae (De partibus animalium 1 2-3) he writes but it abstracts from those characteristics of the world as a working biologist, armed with a set of questions that are the special concern of physics-movement about breathing and sleeping, movement and nourish- and change, and therewith time and location . So the ment, birth and death . nature and behavior of physical things will call for The starting point in tracing his scientific progress more sorts of explanation than mathematics recog- must therefore be his years in the Academy . Indeed nizes. Faced with a man, or a tree, or a flame, one without this starting point it is not possible to under- can ask what it is made of, its "matter" ; what is its stand either his pronouncements on scientific theory essential character or "form" ; what external or in- or, what is more important, the gap between his ternal agency produced it ; and what the "end" or theory and his practice . purpose of it is . The questions make good sense when The Mathematical Model. The Academy that applied to an artifact such as a statue, and Aristotle Aristotle joined in 367 was distinguished from other often introduces them by this analogy ; but he holds Athenian schools by two interests : mathematics (in- that they can be extended to every kind of thing cluding astronomy and harmonic theory, to the extent involved in regular natural change . The explanations that these could be made mathematically respect- they produce can be embodied in the formal proofs able), and dialectic, the Socratic examination of the or even the basic definitions of a science (thus a lunar assumptions made in reasoning including the as- eclipse can be not merely accounted for, but defined, sumptions of mathematicians and cosmologists . as the loss of light due to the interposition of the Briefly, Plato regarded the first kind of studies as earth, and a biological species can be partly defined merely preparatory and ancillary to the second ; Aris- in terms of the purpose of some of its organs) . Again, totle, in the account of scientific and philosophical the regularities studied by physics may be unlike method that probably dates from his Academic years, those of mathematics in an important respect : initially reversed the priorities (Posterior Analytics I ; Topics I the Posterior Analytics depicts a science as deriving 1-2). It was the mathematics he encountered that im- necessary conclusions from necessary premises, true pressed him as providing the model for any well-or- in all cases (I ii and iv), but later (I xxx) the science ganized science . The work on axiomatization which is allowed to deal in generalizations that are true in was to culminate in Euclid's Elements was already far most cases but not necessarily in all .