[105] Plato, Phædrus, p. 271 D-E. δεῖ δὴ ταῦτα ἱκανῶς νοήσαντα, μετὰ ταῦτα θεώμενον αὐτὰ ἐν ταῖς πράξεσιν ὄντα τε καὶ πραττόμενα, ὀξέως τῇ αἰσθήσει δύνασθαι ἐπακολουθεῖν, ἢ μηδὲ εἰδέναι πω πλέον αὐτῶν ὧν τότε ἤκουε λόγων ξυνών.
[106] Plato, Phædrus, p. 270 C.
Plato’s Idéal of the Rhetorical Art — involves in part incompatible conditions — the Wise man or philosopher will never be listened to by the public.
The total, thus summed up by Plato, of what is necessary to constitute an Art of Rhetoric, is striking and comprehensive. It is indeed an idéal, not merely unattainable by reason of its magnitude, but also including impracticable conditions. He begins by postulating a perfectly wise man, who knows all truth on the most important social subjects; on which his country-men hold erroneous beliefs, just as sincerely as he holds his true beliefs. But Plato has already told us, in the Gorgias, that such a person will not be listened to: that in order to address auditors with effect, the rhetor must be in genuine harmony of belief and character with them, not dissenting from them either for the better or the worse: nay, that the true philosopher (so we read in one of the most impressive portions of the Republic) not only has no chance of guiding the public mind, but incurs public obloquy, and may think himself fortunate if he escapes persecution.[107] The dissenter will never be allowed to be the guide of a body of orthodox believers; and is even likely enough, unless he be prudent, to become their victim. He may be permitted to lecture or discuss, in the gardens of the Academy, with a few chosen friends, and to write eloquent dialogues: but if he embodies his views in motions before the public assembly, he will find only strenuous opposition, or something worse. This view, which is powerfully set forth by Sokrates both in the Gorgias and Republic, is founded on a just appreciation of human societies: and it is moreover the basis of the Sokratic procedure — That the first step to be taken is to disabuse men’s minds of their false persuasion of knowledge — to make them conscious of ignorance — and thus to open their minds for the reception of truth. But if this be the fact, we must set aside as impracticable the postulate advanced by Sokrates here in the Phædrus — of a perfectly wise man as the employer of rhetorical artifices. Moreover I do not agree with what Sokrates is here made to lay down as the philosophy of Error:— that it derives its power of misleading from resemblance to truth. This is the case to a certain extent: but it is very incomplete as an account of the generating causes of error.
[107] Plato, Gorg. p. 513 B, see supra, [ch. xxiv.]; Republic, vi. pp. 495-496.
The other part of the Platonic Idéal is grand but unattainable — breadth of psychological data and classified modes of discourse.
But the other portion of Plato’s sum total of what is necessary to an Art of Rhetoric, is not open to the same objection. It involves no incompatible conditions: and we can say nothing against it, except that it requires a breadth and logical command of scientific data, far greater than there is the smallest chance of attaining. That Art is an assemblage of processes, directed to a definite end, and prescribed by rules which themselves rest upon scientific data — we find first announced in the works of Plato.[108] A vast amount of scientific research, both inductive and deductive, is here assumed as an indispensable foundation — and even as a portion — of what he calls the Art of Rhetoric: first, a science of psychology, complete both in its principles and details: next, an exhaustive catalogue and classification of the various modes of operative speech, with their respective impression upon each different class of minds. So prodigious a measure of scientific requirement has never yet been filled up: of course, therefore, no one has ever put together a body of precepts commensurate with it. Aristotle, following partially the large conceptions of his master, has given a comprehensive view of many among the theoretical postulates of Rhetoric; and has partially enumerated the varieties both of persuadable auditors, and of persuasive means available to the speaker for guiding them. Cicero, Dionysius of Halikarnassus, Quintilian, have furnished valuable contributions towards this last category of data, but not much towards the first: being all of them defective in breadth of psychological theory. Nor has Plato himself done anything to work out his conception in detail or to provide suitable rules for it. We read it only as an impressive sketch — a grand but unattainable idéal — “qualem nequeo monstrare et sentio tantum”.
[108] 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):