CHAP. XVII. But a second something is necessary besides cor- It is proved motion being Democritus had resolved the two conceptions of body and empty space into the conceptions of being and not being, but true to his position, Epicurus dispensed with this speculative basis: he holds to the ordinary notions of empty space, and of a material filling space, and simply proves these notions by the qualities of phenomena. But for this very reason 4 A distinction between abstract 1 Lucret. i. 358. 2 Lucret. 1. c. and i. 329; Diog. 40 and 67; Sext. Math. vii. 213; viii. 329. Most of the remarks in Lucret. i. 346 and 532 point to the same fundamental idea: Without vacant interstices, nourishment cannot be diffused over the whole bodies of plants or animals, nor could sand, cold, fire, and water penetrate through solid bodies, or any body be broken up into parts. Themist. 40, b; Simpl. De Cœlo, Schol. in Arist. 484, a, 26. Lucr. i. 440; Diog. 39; Plut. Adv. Col. 11, 5. Body is defined by Epicurus (Sext. Math. i. 21; x. 240; 257; xi. 226) as το τριχῆ διαστατὸν μετὰ ἀντιτυπίας, or as σύνοδος κατὰ ἀθροισμὸν μεγέθους καὶ σχήμATOS Kai àνTITUælas кal Bápovs. Emptiness is (according to Sext. π. 2) φύσις ἀναφὴς or ἔρημος παν Tos ouaTos. When occupied by a body, it is called Tónos; when bodies pass through it, it is xapa; so that all three expressions, as Stob. Ecl. i. 388, rightly observes, are only different names for the same thing. Democritus' division of body into innumerable primary particles or atoms appeared to him most necessary. All bodies known to us by sensation are composed of parts. If the process of division were to go on for ever all things would ultimately be resolved into the non-existent-so Epicurus and Democritus argue-and conversely all things must have arisen out of the non-existent, in defiance of the first principle of natural science that nothing can come from the non-existent, and that nothing can be resolved into what is non-existent. Hence, Hence, in Diog. 69, apoioua and σvμτepоphμevov are used of bodies; in Diog. 71, all bodies are called σvμтúμата; and, according to Epicurus (Sext. Math. x. 42), all changes in bodies are due to local displacement of the atoms. Plut. Amator. 24, 3, observes that Epicurus deals with ἁφὴ and συμπλοκή, but never with ἑνότης. 2 Epic. in Diog. 40: Twv owudτων τὰ μέν ἐστι συγκρίσεις τὰ δ' ἐξ ὧν αἱ συγκρίσεις πεποίηνται· ταῦτα δέ ἐστιν ἄτομα καὶ ἀμετάβλητα εἴπερ μὴ μέλλει πάντα εἰς τὸ μὴ ὂν φθαρήσεσθαι, ἀλλ' ἰσχύοντα ὑπομένειν ἐν ταῖς διαλύσεσι τῶν συγκρίσεων WOTE Tàs ἀρχὰς ἀτόμους ἀναγκαῖον εἶναι σω μáτwv pÚJEιs. Ibid. 56; Lucr. i. 147; ii. 551; 751; 790. Further arguments for the belief in atoms in Lucret. i. 498: Since a body and the space in which it is are entirely different, both must originally have existed without any intermingling. If things exist composed of the full and the empty, the full by itself must exist, and likewise the empty. EE CHAP, XVII. СНАР. XVII. we must conclude that the primary component parts of things can neither have come into existence nor cease to exist, nor yet be changed in their nature.1 These primary bodies contain no empty space in themselves, and hence can neither be divided nor destroyed, nor be changed in any way. They are so small that they do not impress the senses, and it is a matter of fact that we do not see them. Nevertheless they must not be regarded as mathematical atoms, the name atoms being only assigned to them because their bodily structure will not admit of division. Moreover, they have neither colour, warmth, smell, nor any other property; properties only belonging to distinct materials; and for this reason they must not be sought in the four elements, all of which, as experience shows, come into being 1 and pass away. They only possess the universal qualities of all corporeal things, viz. shape, size, and weight." 3 Not only must atoms, like all other bodies, have shape, but there must exist among them indefinitely many varieties of shape, or it would be impossible to account for the innumerable differences of things. There cannot, however, be really an infinite number of such shapes as Democritus maintained in any limited body, nor yet in the whole universe,' since an unlimited number would make the arrangement of the world impossible; for in the world everything is circumscribed by certain extreme limits. Again, atoms must be different in point of size; for all materials cannot be divided into particles of equal size; but even to this difference there must be some bounds. An atom must neither be so large as to become an object of sense, nor can it, after what has been said, be infinitely small.3 From difference in point of size the difference of atoms in point of weight follows. In point of number atoms must be unlimited, and in the same way empty space must be unbounded also; for everything bounded must be bounded by something, but it is impossible to imagine any bounds of the universe beyond which nothing exists, and hence there can be no bounds at all. The absence of bounds must apply to the mass of atoms quite as much as to empty space. If an indefinite number of atoms would not find room in a limited space, conversely a limited number of atoms would be lost in empty space, and never able to form a world. In all these views Epicurus closely follows Diog. 42; Lucr. ii. 333 and 478; Plut. Plac. i. 3, 30; Alex. Aphr. in Philop. Gen. et Corr. 3, 6; Cic. N. D. i. 26, 66. It does not appear that Lucret. ii. 333, made the variety of figures as great as the number of atoms. 2 Lucret. i. 500. 3 Diog. x. 55; Lucr. ii. 381. See the passages just quoted. Epic. in Diog. 41: ảnλà μǹy xa rò tây ắpor Bo TV TO gặp TεTEраσμÉνоV Čкpov EXEL TO 8' ἄκρον παρ' ἕτερόν τι θεωρεῖται. ὥστε οὐκ ἔχον ἄκρον πέρας οὐκ ἔχει, πέρας δ' οὐκ ἔχον ἄπειρον ἂν εἴη καὶ οὐ πεπερασμένον. The same argument is used by Lucret. i. 951; 1008-1020: If space were limited, all bodies would collect CHAP. XVII. CHAP. XVII. B. The world. (1) The swerving aside of atoms. Democritus, and, no doubt, also agrees with him in the way in which he deduces the qualities of things from the composition of atoms.' In deducing the origin of things from their primary causes, Epicurus, however, deviates widely from his predecessor. Atoms-so it was taught by both-are by virtue of their weight engaged in a downward motion.2 To Epicurus it seemed a matter of course that all bodies should move downwards in empty space; for whatever is heavy must fall unless it is supported. He was therefore opposed to the Aristotelian view that heaviness shows itself in the form of attraction towards a centre, and consequently to his further supposition that downward towards its lower part by reason We have but little informa- TηTOS. According to the difference of constitution, it has on some a cooling, on others a heating effect. Plut. Qu. Conviv. iii. 5, 1, 4; Adv. Col. 6. 2 Diog. 43; 47; Cic. N. D. i. 20, 54. What idea Epicurus formed to himself of motion we are not told. We learn, however, from Themist. Phys. 52, b, that he replied to Aristotle's proof of motion, that no constant quantities can be composed of indivisible particles, by saying: Whatever moves in a given line, moves in the whole line, but not in the individual indivisible portions of which the line consists. With reference to the same question, the Epicureans, according to Simpl. Phys. 219, b, asserted that everything moves equally quickly through indivisible spaces. Cic. Fin. i. 6, 18; Lucret. i. 1074. |