Of His own free-will, moreover, He exercised His divine and human will. For free-will is assuredly implanted in every rational nature. For to what end would it possess reason, if it could not reason at its own free-will? For the Creator hath implanted even in the unreasoning brutes natural appetite to compel them to sustain their own nature. For devoid of reason, as they are, they cannot guide their natural appetite but are guided by it. And so, as soon as the appetite for anything has sprung up, straightway arises also the impulse for action. And thus they do not win praise or happiness for pursuing virtue, nor punishment for doing evil. But the rational nature, although it does possess a natural appetite, can guide and train it by reason wherever the laws of nature are observed. For the advantage of reason consists in this, the free-will, by which we mean natural activity in a rational subject. Wherefore in pursuing virtue it wins praise and happiness, and in pursuing vice it wins punishment.