¹ ‘Science and Arts among the Ancients’, an address given to the Faculties of Arts and Science, University College, London, in 1899, published in Nine Essays (Cambridge, 1927) 16.

² A History of Science and its relations with Philosophy and Religion (Cambridge, 1929) 28. Compare, from about the same period, Riley, Woodbridge: ‘Plato … was largely responsible for turning back the clock of scientific progress. To explain the workings of the world he preferred imagination to observation’ (From Myth to Reason [New York and London, 1926] 47).Google Scholar

³ History of Ancient Geography (Cambridge, 1948) 101.

⁴ Greek Science (originally published 1944; revised edition, 1961) 120.

⁵ Adventures of Ideas (Cambridge, 1933) 194.

⁶ Science and the Modern World (Cambridge, 1926) 41.

⁷ Proceedings of the American Philosophical Society lxvi (1927) 159–182. See also the papers of Field, G. C., ‘Plato and Natural Science’ in Philosophy viii (1933) 131–141CrossRefGoogle Scholar, and Edelstein, L., ‘Platonism or Aristotelianism?’ in Bulletin of the History of Medicine viii (1940) 757–769.Google Scholar

⁸ ‘Gedanken der antiken Naturphilosophie in der modernen Physik’ in Die Antike xiii (1937) 118–126, reprinted in Wandlungen in den Grundlagen der Naturwusenschaft (6th ed Leipzig, 1945), translated by Hayes, F. C. as Philosophic Problems of Nuclear Science (London, 1952).Google Scholar

⁹ Popper, K. R., ‘The Nature of Philosophical Problems and their roots in Science’ in British Journal for the Philosophy of Science iii (1952) 124–156Google Scholar, reprinted in Conjectures and Refutations (London, 1963) 66–96. Friedländer, P., Platon I, Seinswahrheit und Lebenswirklichkeit (Berlin, 1954)Google Scholar, translated by H. Meyerhoff (London, 1958) ch. 14, ‘Plato as Physicist’, 246–260. Cherniss, , ‘Plato 1950–1957’ in Lustrum, iv and v (1959–1960)Google Scholar, especially Section V E ‘Mathematics and the “Sciences”’, 388–425, provides a full bibliography of recent work on Plato's science, to which should now be added the following works especially: Brumbaugh, R. S., ‘Plato and the History of Science’ in Studium Generale xiv (1961) 520–527Google Scholar; Crombie, I. M., An Examination of Plato's Doctrines ii (London, 1963) ch. 2Google Scholar, ‘Cosmology and Theory of Nature’, 153–246; and Witte, B., ‘Der εἰκὼς λόγος im Platos Timaios. Beitrag zur Wissenschaftsmethode und Erkenntnistheorie des späten Plato’ in Archiv fur Geschichte der Philosophie xlvi (1964) 1–16.CrossRefGoogle Scholar

¹⁰ See, for example, Heath, T. L., Aristarchus of Samos (Oxford, 1913) 138–9Google Scholar, commenting on Republic 529a–530b.

¹¹ A Commentary on Plato's Timaeus (Oxford, 1928) 11.

¹² In a note in his Loeb edition of the Republic ii (1935) 187.

¹³ See, for example, Republic 521cd, 523ab, 524c, 525b–e, 526ab.

¹⁴ See Republic 530a7–b4, and contrast Aristotle's belief in the unchanging nature of the heavens, e.g. Cael. 270b 11 ff.

¹⁵ There is a similar ambiguity in many of Plato's statements referring to particulars and to sensation, e.g. at Republic 523b3–4 and Phaedo 65b1–6.

¹⁶ Compare Crombie, op. cit. ii 187.

¹⁷ This is clear from Glaucon's remark at 530C2–3 (already quoted) and from 529C4 ff.

¹⁸ (Republic 531a1–3).In his haste to criticise the empiricists for not ascending to problems (cf. 531c), Plato appears to deny that empirical methods have any value at all.

¹⁹ E.g. Ti. 47ab, where Timaeus acknowledges the part that sight has played in the invention of number and in the origin of the study of nature and in that of philosophy itself:

²⁰

²¹ Cornford, , Plato's Cosmology (London, 1937) 29–30.Google Scholar

²² Other typical passages where Timaeus claims that his account is the ‘most likely’ one or ‘second to none in probability’ are 44.cd, 48d and 67d. At 56b he goes further and says that they may take it that the pyramid is the ‘element and seed’ of fire ‘in accordance with the correct account as well as with the probable one’

²³ Cf. Cornford, op. cit. 6: ‘The chief purpose of the cosmological introduction is to link the morality externalised in the ideal society to the whole organisation of the world.… That human morality is so based on the cosmic order had been implied, here or there, in earlier works; but the Timaeus will add something more like a demonstration, although in mythical form’. Cf. also Crombie, op. cit. ii 230 ff.

²⁴

²⁵ For one attempted reconstruction of the reason Plato may have had in mind see Cornford, op. cit. 214 f. and 231 ff.; for another Popper, op. cit. 90 f.

²⁶ Cf. also 54b 1–2.

²⁷ He uses the term τιθέμεθα at 54a5–6.

²⁸ The MSS vary, however, between παιδιάν and παιδείαν at 59d2.

²⁹ See Cornford, op. cit. 276 ff., and for a contrasting interpretation cf. Crombie, op. cit. ii 228 f.

³⁰ Compare μειγνύναι and κεραννύναι used of the mixture of fire and water or of fire and fire at 68b2 and b3–4, with the same verbs used of mixtures of colours such as ‘red’ ‘white’ and ‘bright’ at 68b5, c1, c2, c4–5 and c7.

³¹ Cornford, op. at. 278.

³² The relation between Plato and contemporary medicine has been much discussed in recent years: see especially Abel, K., Gesnerus xiv (1957) 94–118Google Scholar; Schuhl, P. M., REG lxxiii (1960) 73–9CrossRefGoogle Scholar; Wichmann, O., Forschungen und Fortschritte xxxiv (1960) 14–8Google Scholar; Joly, R., Bulletin de l'association G. Budé xx (1961) 435–51Google Scholar; Miller, H. W., Transactions and Proceedings of the American Philological Association xciii (1962) 175–87.CrossRefGoogle Scholar

³³ See, for example, Solmsen, F., Aristotle's System of the Physical World (New York, 1960) 41 ff.Google Scholar and cf. Keyt, D., ‘Aristotle on Plato's Receptacle’ in American Journal of Philology lxxxii (1961) 291–300.CrossRefGoogle Scholar

³⁴ Ti. 48d4 ff., 53b7 ff. cf. 48b5 ff.

³⁵ Plato does not, however, allow earth to change into any of the other kinds (Ti. 56d) presumably because of the geometry of his theory of the construction of the four simple bodies (earth, identified with the cube, is constructed from right-angled isosceles triangles, while the other three simple bodies are constructed from right-angled scalene triangles) rather than because of any empirical considerations.

³⁶ E.g. Ti. 57c. Friedländer, op. cit. 255, tentatively suggests that the different varieties or grades of each simple body might be referred to as ‘isotopes’.

³⁷ Only two of the extant fragments of Empedocles make specific suggestions concerning the actual proportions of the four roots in compound bodies (frr. 96 and 98 dealing with bone, blood and the ‘various forms of flesh’). To what extent Empedocles put forward other similar suggestions in his poem we do not know, but it is generally thought to be unlikely that he developed his theory in any great detail.

³⁸ 58c–61c. In dealing with the varieties and compounds of earth and water, for instance, he considers such properties as whether a substance is soluble or insoluble in water, whether it is fusible by fire and so on (60C5, d3, d7, e3 etc). With this one may compare the more detailed discussion of the properties of natural substances and the attempt to classify them into broad groups in the fourth book of the Meteorologica (e.g. 384a3 ff., 388a29 ff.), and the even more detailed analysis of minerals in Theophrastus’ De Lapidibus.

³⁹ The existence of the void is denied at 58a, 59a, 79b and 80c, and Plato explains motion on the doctrine of the ‘circular thrust’ (79a, 79e ff., especially 80c). Popper remarks that ‘Plato seems to have been the first to see, if only dimly, that in a full world circular or vortex-like motion is possible, provided that there is a liquid-like medium in the world’ (op. cit. 81, n. 22) and comments interestingly that ‘Plato's reconciliation of atomism and the theory of the plenum (‘nature abhors the void’) became of the greatest importance for the history of physics down to our own day’ (op. cit. 88, n. 45). Even before Plato, however, Empedocles, for example, had both explicitly denied the existence of a void (frr. 13 and 14) and asserted the possibility of motion.

⁴⁰ Whether the identification of the simple bodies and these four regular solids had already been made by Philolaus is a much disputed question. Sachs, E., Die fünf platonischen Körper, Philologische Untersuchungen 24 (Berlin, 1917) 69 ff.Google Scholar, and Burkert, W., Weisheit und Wissenschaft (Nurnberg, 1962) 62 f., 426 ff.Google Scholar, for example, have denied this, but Guthrie, W. K. C., who discusses the evidence in A History of Greek Philosophy i (Cambridge, 1962) 266 ff.Google Scholar, concludes cautiously (269): ‘on balance the evidence inclines us to believe that the correlation of solids and elements was not impossible for Philolaus. More than that it does not allow us to say.’

⁴¹ See Ti. 56d ff.

⁴² As has often been remarked, Plato nowhere gives an explicit account of how the surfaces of the primary bodies disintegrate and recombine to form other figures: nor is it clear how the primary solids can be described as bodies at all, when they are geometrical entities constructed out of plane surfaces.

⁴³ See especially the passage in which he sets out his reasons for assigning the various simple bodies to the regular solids (55d ff.).

⁴⁴ Galen, for instance, sees fit to comment on Plato's pathology at some length, for example in De plac. Hipp. et Plat., although he remarks at one point (op. cit. viii ch. 5) that the frequent commentators on the Timaeus devoted much less attention to the medical theories it contains than to other parts of the work.

⁴⁵ See especially On the Sacred Disease which attributes that disease (epilepsy) to phlegmatic fluxes from the brain (chaps. 3 ff., vi 366 5 ff. Littré); cf. On Breaths ch. 14 (CMG i 1.99 20 ff.). In the philosophers, too, we find certain suggestions made concerning the physical basis of psychological disorders: see for example Heraclitus fr. 117 and cf. fr. 118. A late source (Caelius Aurelianus) attributes to Empedocles a distinction between two sorts of madness one of which has its origin in the imbalance in the body (Morb. Chron. i 5, DK 31, A 98, on which see Guthrie, op. cit. ii 227 f.). And in fr. 191 Democritus speaks of excessive pleasure disturbing the movements of the soul.

⁴⁶ On Taylor's view, that the doctrine enunciated by Timaeus in this passage is a determinist one ‘which makes moral freedom and responsibility illusory’, see Cornford, op. cit. 343 f. and 346 ff.

⁴⁷ See for example 82d6, and cf. 81b–d in the account of growth and death.

⁴⁸ For a recent discussion of the merits of Plato's pathology see Miller, H. W., ‘The aetiology of disease in Plato's Timaeus’ in Transactions and Proceedings of the American Philological Association xciii (1962) 175–87CrossRefGoogle Scholar, who argues strongly against the view that Plato's treatment is ‘merely derivative, eclectic and synthetic’.

⁴⁹ See Anon. Lond. xx 43 ff. Whether Empedocles had a similar notion is disputed (see next note).

⁵⁰ This much is clear from Empedocles fr. 100. In other respects, however, the interpretation of his theory of respiration and of his comparison with the clepsydra is disputed, particularly the question of whether in fr. 100 he was referring to breathing through the nose (as Aristotle held) or through pores in the skin (as has often or indeed generally been supposed in modern times) or through both. The literature on this topic is extensive, but the most important recent contributions are those of Furley, (JHS lxxvii [1957] 31–4)CrossRefGoogle Scholar and Booth, (JHS lxxx [1960] 10–15).CrossRefGoogle Scholar

⁵¹ The best general discussion of the comparison and of Plato's theory of respiration as a whole is that in Cornford, op. at. 306 ff.: cf. however Solmsen, F., ‘On Plato's Account of Respiration’ in Studi Italiani di Filologia Classica xxvii–xxviii (1956) 544–8Google Scholar, who rightly corrects Cornford's interpretation of the role of ‘the hot’ in Plato's theory.

⁵² The fire is described as being connected with (συνημμένον) the air/breath, which is why the two move together. Otherwise the fire, being composed of smaller particles, might have been expected to penetrate through the air: see Taylor, op. cit. 556–7.

⁵³ See Aristotle's comment on Democritus' theory of soul at De An. 405a8 ff., where he attributes to Democritus the idea that soul and mind are the same thing, and this is one of the primary and indivisible bodies,

⁵⁴ Plato further applies his notion of the disintegration of the primary triangles to explain natural death (81b ff.): and the notion of ‘circular thrust’ is appealed to, very briefly, as the explanation of a wide variety of physical phenomena (79e–8oc).

⁵⁵ Plato's contributions to astronomy fall outside the scope of this paper. But I should note that even though the originality of the often rather obscure theories of the Republic, Timaeus, Laws and doubtfully authentic Epinomis is hard to assess, if we may credit the opinion of Sosigenes (reported by Simplicius, , in Cael. 488 21 ff.Google Scholar) it was Plato who formulated for his contemporaries the problem of planetary motion: ‘by the assumption of what uniform and orderly motions can the apparent motions of the planets be accounted for?’ In a sense, of course, the search for regularities and order in the movements of the heavenly bodies is as old as theoretical astronomy itself, and the speculations of Anaximander and the Pythagoreans can be seen as attempts to reduce celestial motions to an orderly pattern. But this hardly detracts from the importance of the first clear formulation of the problem of planetary motion as such, and this was to remain the central problem of astronomy not only throughout antiquity, but down to Newton, although the conditions for the solution of the problem changed (in particular the requirement of circular motion was abandoned, of course, after Kepler).

⁵⁶ Chalcidius, (in Ti. 256 f., Waszink)Google Scholar reports that Alcmaeon undertook the excision of the eye. It is notable, however, how few of the Hippocratic treatises refer to the use of dissection, and of those that do by far the most important and striking, On the Heart, has generally been thought to be later than the majority of the works in the Corpus (see Bourgey, , Observation et expérience chez les médecins de la Collection Hippocratique [Paris, 1953] 39 f.)Google Scholar, sometimes a good deal later (see Abel, K., ‘Die Lehre vom Blutkreislauf im Corpus Hippocraticum’ in Hermes lxxxvi [1958] 201 f.Google Scholar, who puts the author after Erasistratus).

⁵⁷ Compare such treatises as On Breaths or On Regimen i.

⁵⁸ 68e f., quoted above, 83–84. Cf. ako 46e where Timaeus says that they must speak of both those causes that work with reason to produce what is good, and the causes that are without intelligence and produce random effects without order, and 48ab.

⁵⁹ Op. cit. 93. On the historical question of the influence of Plato and Platonism on Renaissance science, see, for example, Popper, op. cit. 89 and Koyré, A., ‘Galileo and Plato’ in Journal of the History of Ideas iv (1943) 400–28.CrossRefGoogle Scholar

⁶⁰ Plato's Progress (Cambridge, 1966) 13.

⁶¹ Hackforth suggested that what Plato had in mind in the expression ‘what is most akin to them’ is the subject-matter of astronomy (Plato's Examination of Pleasure [Cambridge, 1958] 122 n. 2).

⁶² At 58e–59b Socrates expressly remarks that anyone who studies nature and such questions as how this world came to be is investigating not that which always is, but only what is coming to be, and so is concerned with opinions, not with exact truth. Hackforth remarked (op. cit. 121 n. 1) that ‘the language suggests a personal allusion, and it is not impossible that Plato is thinking of Democritus’, but he went on to note: ‘the attitude to cosmology, and to physical science in general, is fully consonant with that of the Timaeus’.

⁶³ Nevertheless without attempting a systematic classification of the arts Plato does draw distinctions between different kinds on certain occasions, as for example when he distinguishes between the productive and the imitative arts in Republic x 597a ff.

⁶⁴ One might compare the terms ὄντα, ὄν and οὐσία used (1) generically, of the whole of reality including both Forms and particulars, and (2) particularly, of the highest reality, the Forms, alone. See for example Phaedo 79a which speaks of and cf. Sophist 249a–d where for example not only κίνησις but also τὸ κινούμενον are said ‘to be’ συγχωρητέον ὡς ὄντα.