The Three Parts of the Soul

All faults have one source and origin. But the passions and corruptions are given different names according to the character of the part, or the member, if I may call it that, of the soul that has been harmed. Bodily diseases sometimes show the same thing. Though their cause is one and the same, they are divided into different kinds of illness according to the nature of the member affected. When the force of a harmful fluid has seized the body’s citadel, that is, the head, it produces a headache. When it affects the ears or the eyes, it turns into the illness of earache or inflamed eyes. When it spreads to the joints and the ends of the hands, it is called gout in the joints or in the hands. But when it goes down to the ends of the feet, its name changes and it is called podagra. And the harmful fluid, which in origin is one and the same, is called by as many names as there are separate members that it affects. [a]

In the same way, to pass from visible things to invisible ones, we should hold that the tendency to each fault lies in the parts and, if I may use the expression, the members of our soul. Some very wise men have taught that its powers are three: the reasoning part, the part that feels anger, and the part that desires. One or another of these is sure to be troubled by some attack. So when the force of a harmful passion takes hold of anyone through these feelings, the fault is named according to the part affected. If the plague of sin has infected the reasoning part, it will produce the sins of empty glory, conceit, envy, pride, presumption, strife, and heresy. If it has wounded the part that feels anger, it will give birth to rage, impatience, sulkiness, acedia, faintheartedness, and cruelty. If it has affected the part that desires, it will be the parent of gluttony, sexual immorality, greed, avarice, and harmful and earthly desires.