X. But it may be as well to give an explanation and definition of the word good, which, has been so often employed in this discourse. But the definitions of those philosophers differ a good deal from one another, and yet have all reference to the same facts. I myself agree with Diogenes, who has defined good to be that which in its nature is perfect. But that which follows, that which is profitable (for so we may translate his ὼφέλημα), he considered to be a motion, or a state, arising out of the nature of the perfect. And as the notions of things arise in the mind, if anything has become known either by practice, or by combination, or by similitude, or by the comparison of reason; then by this fourth means, which I have placed last, the knowledge of good is arrived at. For when, by a comparison of the reason, the mind ascends from those things which are according to reason, then it arrives at a notion of good. And this good we are speaking of, we both feel to be and call good, not because of any addition made to it, nor from its growth, nor from comparing it with other things, but because of its own proper power. For as honey, although it is very sweet, is still perceived to be sweet by its own peculiar kind of taste, and not by comparison with other things; so this good, which we are now treating of, is indeed to be esteemed of great value; but that valuation depends on kind and not on magnitude. For as estimation, which is called ἀξί, is not reckoned among goods, nor, on the other hand, among evils, whatever you add to it will remain in its kind. There is, therefore, another kind of estimation proper to virtue, which is of weight from its character, and not because of its increasing. Nor, indeed, are the perturbations of the mind, which make the lives of the unwise bitter and miserable, and which the Greeks call πάθη, (I might translate the word itself by the Latin morbi, but it would not suit all the meanings of the Greek word; for who ever calls pity, or even anger, a disease—morbus)? but the Greeks do call such a feeling πάθος. Let us then translate it perturbation, which is by its very name pointed out to be something vicious. Nor are these perturbations, I say, excited by any natural force; and they are altogether in kind four, but as to their divisions they are more numerous. There is melancholy, fear, lust, and that feeling which the Stoics call by the common name which they apply to both mind and body, ἡδονὴ, and which I prefer translating
