Answer of Menon — plurality of virtues, one belonging to each different class and condition. Sokrates enquires for the property common to all of them.
Menon proceeds to answer that there are many virtues: the virtue of a man — competence to transact the business of the city, and in such business to benefit his friends and injure his enemies: the virtue of a woman — to administer the house well, preserving every thing within it and obeying her husband: the virtue of a child, of an old man, a slave, &c. There is in short a virtue — and its contrary, a vice — belonging to each of us in every work, profession, and age.[5]
[5] Plato, Menon, p. 72 A. καθ’ ἑκάστην γὰρ τῶν πράξεων καὶ τῶν ἡλικῶν πρὸς ἕκαστον ἔργον ἑκάστῳ ἡμῶν ἡ ἀρετή ἐστιν. ὡσαύτως δὲ καὶ ἡ κακία.
Though Sokrates disapproves this method of answering — τὸ ἐξαριθμεῖν τὰς ἀρετάς (to use the expression of Aristotle) — yet Aristotle seems to think it better than searching for one general definition. See Politica, i. 13, p. 1260, a. 15-30, where he has the Platonic Menon in his mind.
But (replies Sokrates) are they not all the same, quatenus virtue? Health, quatenus Health, is the same in a man or a woman: is not the case similar with virtue? Menon. — Not exactly similar. Sokr. — How so? Though there are many diverse virtues, have not all of them one and the same form in common, through the communion of which they are virtues? In answer to my question, you ought to declare what this common form is. Thus, both the man who administers the city, and the woman who administers the house, must act both of them with justice and moderation. Through the same qualities, both the one and the other are good. There is thus some common constituent: tell me what it is, according to you and Gorgias? Menon. — It is to be competent to exercise command over men.[6] Sokr. — But that will not suit for the virtue of a child or a slave. Moreover, must we not superadd the condition, to command justly, and not unjustly? Menon. — I think so: justice is virtue. Sokr. — Is it virtue — or is it one particular variety of virtue?[7] Menon. — How do you mean? Sokr. — Just as if I were to say about roundness, that it is not figure, but a particular variety of figure: because there are other figures besides roundness. Menon. — Very true: I say too, that there are other virtues besides justice — namely, courage, moderation, wisdom, magnanimity, and several others also. Sokr. — We are thus still in the same predicament. In looking for one virtue, we have found many; but we cannot find that one form which runs through them all. Menon. — I cannot at present tell what that one is.[8]
[6] Plato, Menon, p. 73 D.
[7] Plato, Menon, p. 73 E. Πότερον ἀρετή, ὦ Μένων, ἢ ἀρετή τις;
[8] Plato, Menon, p. 74 A. οὐ γὰρ δύναμαί πω, ὦ Σώκρατες, ὡς σὺ ζητεῖς, μίαν ἀρετὴν λαβεῖν κατὰ πάντων.
Analogous cases cited — definitions of figure and colour.
Sokrates proceeds to illustrate his meaning by the analogies of figure and colour. You call round a figure, and square a figure: you call white and black both colour, the one as much as the other, though they are unlike and even opposite.[9] Tell me, What is this same common figure and property in both, which makes you call both of them figure — both of them colour? Take this as a preliminary exercise, in order to help you in answering my enquiry about virtue.[10] Menon cannot answer, and Sokrates answers his own question. He gives a general definition, first of figure, next of colour. He first defines figure in a way which implies colour to be known. This is pointed out; and he then admits that in a good definition, suitable to genuine dialectical investigation, nothing should be implied as known, except what the respondent admits himself to know. Figure and colour are both defined suitably to this condition.[11]