Note 79 — Chapter XXXVIII · TIMÆUS AND KRITIAS.

Plato, Tim. pp. 62-64 B. Demokritus appears to have held on this point an opinion approaching to that of Plato. See Democr. Frag. ed. Mullach, pp. 204-215: Aristot. Metaph. A. p. 985, b. 15; De Sensu, s. 62-65; Sextus Empiric. adv. Math. vii. 135.

Περὶ μὲν οὖν βαρέος καὶ κούφου καὶ σκληροῦ καὶ μαλακοῦ, ἐν τούτοις ἀφορίζει — τῶν δ’ ἄλλων αἰσθητῶν οὐδενὸς εἶναι φύσιν, ἀλλὰ πάντα πάθη τῆς αἰσθήσεως ἀλλοιουμένης. We may remark that Plato includes hardness and softness, the different varieties of resistance, among the secondary or relative qualities of matter; all that he seems to conceive as absolute are extension and figure, the geometrical conception of matter. In the view of most modern philosophers, resistance is considered as the most obviously and undeniably absolute of all the attributes of matter, as that which serves to prove that matter itself is absolute. Dr. Johnson refuted the doctrine of Berkeley by knocking a stick against the ground; and a similar refutation is adopted in words by Reid and Stewart (see Mill’s System of Logic, Book vi. ad finem, also Book i. ch. 3, s. 7-8). To me the fact appealed to by Johnson appears an evidence in favour of Berkeley’s theory rather than against it. The Resistant (ὃ παρέχει προσβολὴν καὶ ἐπαφήν τινα, Plato, Sophist. p. 246 A) can be understood only as a correlate of something which is resisted: the fact of sense called Resistance is an indivisible fact, involving the implication of the two. In the first instance it is the resistance experienced to our own motions (A. Bain, The Senses and the Intellect, p. 91, 3rd ed.), and thus involves the feeling of our own spontaneous muscular energy.

The Timæus of Plato is not noticed by Sir W. Hamilton in his very learned and instructive Dissertation on the Primary and Secondary Qualities of Body (notes to his edition of Reid’s Works, p. 826), though it bears upon his point more than the Theætêtus, which he mentions.