VIRTUE AS A HARMONY; VICE AS A DISHARMONY.
2. What occurs in the soul when she contains a vice? We ask this because it is usual to say, "to snatch a vice from the soul;" "to introduce virtue into her," "to adorn her," "to replace ugliness by beauty in her." Let us also premiss, following the opinions of the ancients,[30] that virtue is a harmony, and wickedness the opposite. That is the best means to solve the problem at issue. Indeed, when the parts of the soul (the rational part, the irascible part, and the part of appetite), harmonize with each other, we shall have virtue;[31] and, in the contrary case, vice. Still, in both cases, nothing foreign to the soul enters into her; each of her parts remain what they are, while contributing to harmony. On the other hand, when there is dissonance, they could not play the same parts as the personnel of a choric ballet, who dance and sing in harmony, though not all of them fill the same functions; though one sings while the remainder are silent; and though each sings his own part; for it does not suffice that they all sing in tune, they must each properly sing his own part. In the soul we therefore have harmony when each part fulfils its functions. Still each must have its own virtue before the existence of a harmony; or its vice, before there is disharmony. What then is the thing whose presence makes each part of the soul good or evil? Evidently the presence of virtue or vice. The mere statement that, for the rational part (of the soul) vice consists in ignorance,[32] is no more than a simple negation, and predicates nothing positive about reason.