inevitable consequence. But man's capacity for virtue being equally a capacity for vice, in other words, not strictly speaking a capacity at all, it follows that man must be determined either to virtue or to vice by something different from such a capacity, and that by which he is determined is the power or principle of free-will (προαίρεσις).
30. Inasmuch, then, as man has no natural capacity of virtue, but only a capacity of being either virtuous or vicious, the question arises, How does man become determined either to a virtuous or to a vicious course of action? The answer is, that he is determined to the one or other of these through a power of free-will or choice (προαίρεσις), and not through any natural capacity. But this power of choice is not sufficient to make him either virtuous or vicious. He must acquire the one or the other of these dispositions through custom, as has been already pointed out to you. By the practice of virtue he acquires the habit, ἕξις, of virtue; by the practice of vice he acquires the habit of vice. In fact, this is a case in which δύναμις rather follows ἐνέργεια. In the case of the natural δύναμις the power or capacity precedes, the act, ἐνέργεια, follows, and the ἐνέργεια does not react, or reacts but little, on the δύναμις in the way of strengthening or confirming it. But in the virtues, and also in the operations involved in the different acts, ἐνέργεια comes first, and δύναμις follows; the capacity is created by the practice, the practice
