At times we may perceive in ourselves a state of mind in which we do desire a given thing, but we are indignant with ourselves for having desired it: Our mental state may be that of self-disgust; we feel self-anger. These various feelings are all human emotions, and they exemplify a third element of the mind, or soul.
Thus the essential aspects of the mind follow: (1) reason; (2) emotions or the "spirited" element; and (3) desire, or passions. These aspects of the mind correspond to the three classes of the state: reason, to the rulers; emotions or things spirited, to the auxiliaries; and desire or passions (concupiscence is the term Plato adopts) to the craftsmen.
At this point, we discern the four virtues in the individual. In exercising his reason, in which he has been schooled, a man comes to wisdom. In exercising his emotions or spirit, in which he has been schooled, a man displays courage. In permitting his reason to rule over his emotions and desires, a man displays his temperance. What then of justice?
Justice may be said to ensue from temperance, a kind of mental harmony, a state in which all elements of his mind are in concord with one another. As in the state, a tacit (self-evident) agreement must be reached: Reason must be permitted to rule over the emotions and spirited element and permitted to rule over the desires/passions. Thus is justice secured.
