Note 108 — Chapter XXVI · PHÆDRUS — SYMPOSION.

I repeat the citation from the Phædrus, one of the most striking passages in Plato, p. 271 D.

ἔπειδὴ λόγου δύναμις τυγχάνει ψυχαγωγία οὖσα, τὸν μέλλοντα ῥητορικὸν ἔσεσθαι ἀνάγκη εἰδέναι ψυχὴ ὅσα εἴδη ἔχει. ἔστιν οὖν τόσα καὶ τόσα, καὶ τοῖα καὶ τοῖα· ὅθεν οἱ μὲν τοιοίδε, οἱ δὲ τοιοίδε γίγνονται. τούτων δὲ δὴ διῃρημένων, λόγων αὖ τόσα καὶ τόσα ἔστιν εἴδη, τοιόνδε ἕκαστον. οἱ μὲν οὖν τοιοίδε ὑπὸ τῶν τοιῶνδε λογων διὰ τήνδε τὴν αἰτίαν ἐς τὰ τοιάδε εὐπειθεῖς, οἱ δὲ τοιοίδε διὰ τάδε δυσπειθεῖς, &c. Comp. p. 261 A.

The relation of Art to Science is thus perspicuously stated by Mr. John Stuart Mill, in the concluding chapter of his System of Logic, Ratiocinative and Inductive (Book vi. ch. xii. § 2):

“The relation in which rules of Art stand to doctrines of Science may be thus characterised. The Art proposes to itself an end to be attained, defines the end, and hands it over to the Science. The Science receives it, considers it as a phenomenon or effect to be studied, and having investigated its causes and conditions, sends it back to Art with a theorem of the combinations of circumstances by which it could be produced. Art then examines these combinations of circumstances, and according as any of them are or are not in human power, pronounces the end attainable or not. The only one of the premisses, therefore, which Art supplies, is the original major premiss, which asserts that the attainment of the given end is desirable. Science then lends to Art the proposition (obtained by a series of inductions or of deductions) that the performance of certain actions will attain the end. From these premisses Art concludes that the performance of these actions is desirable; and finding it also practicable, converts the theorem into a rule or precept.”