[70] It is worth inquiring why courage is mentioned in the second place, self-mastery in the third, and prudence in the first, and why he has not set forth a different order of the virtues. We must observe, then, that our soul is threefold, and has one part that is the seat of reason, another that is the seat of high spirit, and another that is the seat of desire. And we discover that the head is the place and abode of the reasonable part, the breast of the passionate part, the abdomen of the lustful part; and that to each of the parts a virtue proper to it has been attached; prudence to the reasonable part, for it belongs to reason to have knowledge of the things we ought to do and of the things we ought not; courage to the passionate part; and self-mastery to the lustful part. For it is by self-mastery that we heal and cure our desires.
[71] As, then, the head is the first and highest part of the living creature, the breast the second, and the abdomen the third, and again of the soul the reasoning faculty is first, the high-spirited second, the lustful third: so too of the virtues, first is prudence which has its sphere in the first part of the soul which is the domain of reason, and in the first part of the body, namely the head; and second is courage, for it has its seat in high spirit, the second part of the soul, and in the breast, the corresponding part of the body; and third self-mastery, for its sphere of action is the abdomen, which is of course the third part of the body, and the lustful faculty, to which has been assigned the third place in the soul.