Note 203 — Chapter I · SPECULATIVE PHILOSOPHY IN GREECE, BEFORE AND IN THE TIME OF SOKRATES. (continued 2)

It is chiefly in the eighth chapter of the treatise De Gener. et Corr. (i. 8) that Aristotle traces the doctrine of Leukippus as having grown out of that of the Eleates. Λεύκιππος δ’ ἔχειν ᾠήθη λόγους, οἵτινες πρὸς τὴν αἴσθησιν ὁμολογούμενα λέγοντες οὐκ ἀναιρήσουσιν οὔτε γένεσιν οὔτε φθορὰν οὔτε κίνησιν καὶ τὸ πλῆθος τῶν ὄντων, &c.

Compare also Aristotel. De Cœlo, iii. 4, p. 303, a. 6; Metaphys. A. 4, p. 985, b. 5; Physic. iv. 6: λέγουσι δὲ (Demokritus, &c., in proving a vacuum) ἓν μὲν ὅτι ἡ κίνησις ἡ κατὰ τόπον οὐκ ἂν εἴη, οὐ γὰρ ἂν δοκεῖν εἶναι κίνησιν εἰ μὴ εἴη κενόν· τὸ γὰρ πλῆρες ἀδύνατον εἶναι δέξασθαί τι, &c.

Plutarch adv. Kolot. p. 1108. Οἷς οὐδ’ ὄναρ ἐντυχὼν ὁ Κολώτης, ἐσφάλη περὶ λέξιν τοῦ ἀνδρὸς (Demokritus) ἐν ᾖ διορίζεται, μὴ μᾶλλον τὸ δὲν, ἢ τὸ μηδὲν εἶναι· δὲν μὲν ὀνομάζων τὸ σῶμα μηδὲν δὲ τὸ κενόν, ὡς καὶ τούτου φύσιν τινὰ καὶ ὑπόστασιν ἰδίαν ἔχοντος.

The affirmation of Demokritus — That Nothing existed, just as much as Something — appears a paradox which we must probably understand as implying that he here adopted, for the sake of argument, the language of the Eleates, his opponents. They called the vacuum Nothing, but Demokritus did not so call it. If (said Demokritus) you call vacuum Nothing, then I say that Nothing exists as well as Something.

The direct observations by which Demokritus showed the existence of a vacuum were — 1. A vessel with ashes in it will hold as much water as if it were empty: hence we know that there are pores in the ashes, into which the water is received. 2. Wine can be compressed in skins. 3. The growth of organised bodies proves that they have pores, through which new matter in the form of nourishment is admitted. (Aristot. Physic. iv. 6, p. 213, b.)

Besides this, Demokritus set forth motion as an indisputable fact, ascertained by the evidence of sense: and affirmed that motion was impossible, except on the assumption that vacuum existed. Melissus, the disciple of Parmenides, inverted the reasoning, in arguing against the reality of motion. If it be real (he said), then there must exist a vacuum: but no vacuum does or can exist: therefore there is no real motion. (Aristot. Physic. iv. 6.)

Since Demokritus started from these facts of sense, as the base of his hypothesis of atoms and vacua, so Aristotle (Gen. et Corr. i. 2; De Animâ, i. 2) might reasonably say that he took sensible appearances as truth. But we find Demokritus also describing reason as an improvement and enlightenment of sense, and complaining how little of truth was discoverable by man. See Mullach, Demokritus (pp. 414, 415). Compare Philippson — Ὗλη ἀνθρωπίνη — Berlin, 1831.