The attributes of moral agency are intellect, sensibility, and free-will. Moral depravity is the depravity of free-will, not of the faculty itself, but of its free action. It consists in a violation of moral law. Depravity of the will, as a faculty, is, or would be, physical, and not moral depravity. It would be depravity of substance, and not of free, responsible choice.
Moral depravity is depravity of choice.
It is a choice at variance with moral law, moral right. It is synonymous with sin or sinfulness. It is moral depravity, because it consists in a violation of moral law, and because it has moral character. It is the government of free will by motives as distinguished from the government of substance by force. Moral government is indispensable to the highest well-being of the universe of moral agents.