Philo Judaeus Quod Omnis Probus Liber Sit 61

[61] Now the actions which proceed from virtue, the creature man performs, not through compulsion but voluntarily, for everything which he does is the result of his deliberate choice; and the actions which proceed from wickedness, inasmuch as they ought to be avoided, he does not do even in dreams; nor again, is it likely that he would perform those actions which are of an indifferent character, between which the mind, as if in a scale, is equally balanced, not being induced to yield to them, as having any attractive power, nor, on the other hand, to regard them with any particular aversion as worthy of hatred; from all which it is plain, that the virtuous man does nothing against his will, and nothing under compulsion; and if he were a slave he would be acting under compulsion: so that the virtuous man must be free.