- In the field of natural science, Aristotle recognizes as his forerunners a select group of theorists such as Heraclitus of Ephesus, Empedocles of Acragas, Anaxagoras of Clazomenae, and Leucippus and Democritus of Abdera.
- IN the field of natural science, Aristotle recognizes as his forerunners a select group of theorists; he names, individually, barely a dozen. Thales, Anaximander and Anaximenes of Miletus; Heraclitus of Ephesus; Empedocles of Acragas; Anaxagoras of Clazomenae; and Leucippus and Democritus of Abdera: these are the leading lights, though others are occasionally referred to, by name or anonymously. Aristotle takes seriously almost all of these people, treating them as exemplary pioneers and valuable partners in the enterprise of ‘natural philosophy’. Without qualification or irony, he gives them the honourable titles of phusiologos, sophos, philosophos; their activity is sophia, theôria, philosophia, phusiologia (or the corresponding verbs are used: philosophein, theôrein, phusiologein, peri phuseôs skopein).
- The prescriptions of the Topics for dialectical reasoning are clearly relevant to many aspects of Aristotle’s practice in the discussion of foundations. Among the ‘reputable materials’ (endoxa) to which dialectical arguments must appeal, the Topics lists ‘the things held by all or by most people or by the experts (sophois), and, among the experts, by all or most or the most well-known and well-reputed’. The theories of earlier experts on natural science must therefore either be accepted, or shown to be mistaken. If they conflict among themselves, this conflict will constitute one of the initial problems to be resolved, which can be done better once we have taken into account the arguments on both sides. In such cases Aristotle sometimes presents himself as not so much an interested party as an arbitrator, sifting through the inherited mass of conflicting opinion and argument.
- B. Beginnings: The Idea of a Science of Nature
- (1) In the Physics Aristotle expounds and argues for the foundations of his natural science, in doing which he has his predecessors constantly on his mind. The first three books of the Physics, in particular, show that he sees himself as continuing (p. 19) their work. The foundations of natural science are to be identified as such by the application of pre-scientific general reasoning to truths of experience.(2) ‘It is ridiculous to try to demonstrate that there is such a thing as nature’, remarks Aristotle (Phys. II 1 193a3), ‘for it is obvious that there are many such things’. That is, there are many recognizable kinds of thing in the world, and the members of each kind regularly (in the absence of supervening hindrances), and of themselves, originate changes (in themselves and/or in other adjacent things), and/or bring these changes to an end; the changes themselves being classifiable into kinds, and each kind of thing being capable of so originating a certain set of kinds of change. And those kinds of thing that themselves come into being and cease to be, do so as the result of a process originated in this way. These are ‘the things that are by nature’, and that themselves have ‘natures’; while ‘nature’ in the larger sense is constituted by all the various natures of ‘the things that are by nature’, and by their interactions. Aristotle’s ways of using the word phusis (‘nature’) are all dependent on the use that applies it to an individual thing falling into a recognizable kind. This much Aristotle takes to be obvious to all who look at the world, unlike the less obvious entities and relationships that underlie mathematics or ‘first philosophy’.5 It is no surprise, then, that the first attempts at science in Greece were directed at a ‘science of nature’. For Aristotle, serious theoretical effort starts in Greece with Thales of Miletus, the ‘pioneer’ of natural science.6
- (3) How much of his own fully-developed conception of a science does Aristotle ascribe to the early scientists? Metaphysics I 1 relies on distinctions made at Nicomachean Ethics VI 2–7, in stating that ‘all suppose that what is called “wisdom” is concerned with the first causes and the principles’ (981b25–29, referring to EN 1141a9-20). In I 2, the question is then: with what sort of causes and principles? The answer turns out to be: those which are truly primary, i.e., most general and fundamental (982b7–10). For Aristotle these early seekers after wisdom are recognisably scientists. This implies, as Metaphysics I and other texts confirm, that he saw them as, at least, setting up what he recognized as intended to be fundamental principles for a science of everything (‘principles and causes of all things’), and as deducing from those principles, in a way intended to be demonstrative, what he recognized as intended to be scientific explanations of the phenomena of the cosmos.7
C. Foundations: The Principles of Natural Things (Physics I)- (1) At the beginning of Physics I, Aristotle puts himself, for expository purposes, into the position of a would-be natural scientist seeking the principles appropriate for his subject.
- (2) The meaning of the word phusis itself does not get discussed in Physics I, in fact not until Physics II 1.
- (3) The discussion in Physics I 4–6 is an insightful and sympathetic attempt to reconstruct the ways of thinking of Aristotle’s predecessors. Naturally, it is condescending; Aristotle is conscious of being much better equipped than those predecessors were to navigate the logical and philosophical mazes that troubled them.
- (4) Aristotle’s reading of the predecessors in Physics I 4–6 sees their theories as exhibiting significant analogies, or (in modern terms) sharing a common structure. It is the shared structure that is the really valuable part, which is restated in Aristotle’s own terms as the essential truth about the principles of natural change. Then, in Physics I 7, it is deduced by a logos, consisting of a logical analysis of change in general, plus an inductive survey of the kinds of substrate observable in various particular cases.
- D. The Misunderstanding of Nature: (1) False Explanations (Physics II 8–9)
- The second book of the Physics is equally central to Aristotle’s understanding of earlier natural science.
- Even more instructive is Physics II 8–9. The programme for these chapters reads thus: ‘We must say first why nature is among the causes for the sake of something; then we must speak about the necessary, for it is to that cause that everyone reduces [their explanations]: for example, since the hot is of such a nature and the cold and each of such things, these particular things necessarily are and come about.
- Once the need for final cause explanations has been established, it follows that the earlier natural scientists made a fundamental error: not only was this need not seen by any of them; Aristotle claims that without exception they all in effect denied it, by their invocation of ‘the necessary’ as a supposed kind of explanation.
- The ‘nature’ of a thing is defined as ‘a principle of change and of rest’, and the question is then: is the nature of a thing to be identified with its matter or its form? At this point the four causes have not yet been officially introduced; but Aristotle evidently takes the matter-form dichotomy to be already intelligible, just as in Physics I he takes the notion of ‘nature’ itself to be, and presumably for much the same reasons (see B 1 above).
- If, as Physics II 1 implies, we must always explain natural changes only by reference to the natures of things, then it follows that they must not be ascribed to ‘the necessary’, if ‘necessity’ acting on anything is conceived of as something that is superimposed from outside upon the thing’s own nature.
- Conclusion
- 1. The survey in Metaphysics I agrees in sum with the assessment implied by Physics I-III: the earlier natural scientists, after an impressive start, failed to grasp fully (p. 37) the implications of their own enterprise. It was a failure to understand the presuppositions inherent in the notions of science and of nature. The consequent errors in their positive theorising are shown in the Physics. In Metaphysics I, the negative side is revealed: a fumbling approach to the moving cause, and no proper and systematic use of it; effectively no grasp at all of the formal and final causes and of their centrality in the natural world.
- 2. Aristotle’s criticisms of his predecessors can all too easily leave the impression, even after several readings, that he holds them in some contempt. Two principal causes for this, one negative and one positive, are as follows. The negative one: in line with what seems to have been general practice in early Ionian scientific writings, Aristotle rarely if ever acknowledges expressly a particular intellectual debt to a predecessor.34 That is not to say that he tries, or even wishes, to deny or conceal his indebtedness in general. In fact it is clear that he regards himself as the fortunate heir to all that is worthwhile in the heritage of earlier theorising. The positive reason is that in the discussions of predecessors Aristotle’s primary aim is always to establish what he himself takes to be the truth.
- 3. Aristotle is clear in general terms about what fuels the movement towards greater understanding: it is the natural ‘desire to know’ proclaimed in the first sentence of (p. 38) the Metaphysics. What makes it possible for this desire to be fulfilled is the inherent knowability of the truth (since ‘God is not jealous’, Met. I 2 983a2–4). When the attention of those with sufficient leisure is concentrated strongly enough on the problems of science, progress will be made. The subject matter itself will often point inquirers in the right direction.
- 4. Aristotle recognizes too that the chronological sequence is never quite the same as the logical or epistemological one. There are theorists who are ‘ahead of their time’ in recognizing types of causes or substances, or adopting methods, not yet generally recognized; and there are those who are ‘behind their time’, in sticking to a more limited repertoire than others of their contemporaries. Thus the mistake of some Platonists was to pose a problem ‘in an old-fashioned way’ (arkhaikôs: Met. XIV 2 1089a1–2); whereas Anaxagoras, on a certain charitable interpretation, turns out to ‘speak in a rather modern way’ (kainoprepesterôs legein: Met. I 8 989b4–6), and some (p. 39) unnamed theorists ‘though older temporally, had a more modern conception’ (kaiper ontes arkhaioteroi tais hêlikiais kainoterôs enoêsan: De Caelo IV 2 308b30–32).
- 5. Aristotle’s sensitivity and insight, in regard to the historical aspect, is unusual among philosophers. Even accepting that, one may still question the adequacy of Aristotle’s understanding and reporting of his predecessors, and the fairness of his criticisms. One may argue on the basis of other, non-Aristotelian evidence that Aristotle, in good faith or not, misunderstood and misrepresented them; this line of attack, which calls for close scrutiny of that evidence, lies outside the scope of this chapter.
