Diogenes Laertius

καὶ στέλλοντα κατὰ τὰς ἀνακοπάς· εἴ τε τὸ κενὸν ἦν ὡρισμένον, οὐκ ἂν εἶχε τὰ ἄπειρα σώματα ὅπου ἐνέστη.

“Πρός τε τούτοις τὰ ἄτομα τῶν σωμάτων καὶ μεστά, ἐξ ὧν καὶ αἱ συγκρίσεις γίνονται καὶ εἰς ἃ διαλύονται, ἀπερίληπτά ἐστι ταῖς διαφοραῖς τῶν σχημάτων· οὐ γὰρ δυνατὸν γενέσθαι τὰς τοσαύτας διαφορὰς ἐκ τῶν αὐτῶν σχημάτων περιειλημμένων. καὶ καθ᾿ ἑκάστην δὲ σχημάτισιν ἁπλῶς ἄπειροί εἰσιν αἱ ὅμοιαι, ταῖς δὲ διαφοραῖς οὐχ ἁπλῶς 43ἄπειροι ἀλλὰ μόνον ἀπερίληπτοι, [οὐδὲ γάρ φησιν ἐνδοτέρω εἰς ἄπειρον τὴν τομὴν τυγχάνειν. λέγει δέ, ἐπειδὴ αἱ ποιότητες μεταβάλλονται, εἰ μέλλει τις μὴ καὶ τοῖς μεγέθεσιν ἁπλῶς εἰς ἄπειρον αὐτὰς ἐκβάλλειν].

“Κινοῦνταί τε συνεχῶς αἱ ἄτομοι [φησὶ δὲ ἐνδοτέρω καὶ ἰσοταχῶς αὐτὰς κινεῖσθαι τοῦ κενοῦ τὴν εἶξιν ὁμοίαν παρεχομένου καὶ τῇ κουφοτάτῃ καὶ τῇ βαρυτάτῃ.] τὸν αἰῶνα, καὶ αἱ μὲν εἰς μακρὰν ἀπ᾿ ἀλλήλων διιστάμεναι, αἱ δὲ αὐτοῦ τὸν παλμὸν ἴσχουσιν, ὅταν τύχωσι τῇ περιπλοκῇ1 κεκλειμέναι ἢ στεγαζόμενοι παρὰ τῶν πλεκτικῶν.

44“Ἥ τε γὰρ τοῦ κενοῦ φύσις ἡ διορίζουσα ἑκάστην αὐτὴν τοῦτο παρασκευάζει, τὴν ὑπέρεισιν οὐχ οἵα τε οὖσα ποιεῖσθαι· ἥ τε στερεότης ἡ ὑπάρχουσα αὐταῖς κατὰ τὴν σύγκρουσιν τὸν ἀποπαλμὸν ποιεῖ,



to send them back on their upward rebound. Again, if the void were finite, the infinity of bodies would not have anywhere to be.

“Furthermore, the atoms, which have no void in them—out of which composite bodies arise and into which they are dissolved—vary indefinitely in their shapes; for so many varieties of things as we see could never have arisen out of a recurrence of a definite number of the same shapes. The like atoms of each shape are absolutely infinite; but the variety of shapes, though indefinitely large, is not absolutely infinite. [For neither does the divisibility go on “ad infinitum” he says belowa; but he adds, since the qualities change, unless one is prepared to keep enlarging their magnitudes also simply “ad infinitum.”]

“The atoms are in continual motion through all eternity. [Further, he says below,a that the atoms move with equal speed, since the void makes way for the lightest and heaviest alike.] Some of them rebound to a considerable distance from each other, while others merely oscillate in one place when they chance to have got entangled or to be enclosed by a mass of other atoms shaped for entangling.b

“This is because each atom is separated from the rest by void, which is incapable of offering any resistance to the rebound; while it is the solidity of the atom which makes it rebound after a collision,

DOI: 10.4159/DLCL.diogenes_laertius-lives_eminent_philosophers_book_x_epicurus.1925