The Conferences Of John Cassian by John Cassian
Chapter XV. The answer on the threefold movement of the soul.
Abraham: Of all faults there is one source and origin, but different names are assigned to the passions and corruptions in accordance with the character of that part, or member, if I may so call it, which has been injuriously affected in the soul: As is sometimes also shown by the case of bodily diseases, in which though the cause is one and the same, yet there is a division into different kinds of maladies in accordance with the nature of the member affected. For when the violence of a noxious moisture has seized on the body's citadel, i.e., the head, it brings about a feeling of headache, but when it affects the ears or eyes, it passes into the malady of earache or ophthalmia: when it spreads to the joints and the extremities of the hands it is called the gout in the joints or hands; but when it descends to the extremities of the feet, its name is changed and it is termed podagra: and the noxious moisture which is originally one and the same is described by as many names as there are separate members which it affects. In the same way to pass from visible to invisible things, we should hold that the tendency to each fault exists in the parts and, if I may use the expression, members of our soul. And, as some very wise men have laid down that its powers are threefold, either what is logikon, i.e., reasonable, or thumikon, i.e., irascible, or epi thumetikon, i.e., subject to desire, is sure to be troubled by some assault. When then the force of noxious passion takes possession of anyone by reason of these feelings, the name of the fault is given to it in accordance with the part affected. For if the plague of sin has infested its rational parts, it will produce the sins of vainglory, conceit, envy, pride, presumption, strife, heresy. If it has wounded the irascible feelings, it will give birth to rage, impatience, sulkiness, accidie, pusillanimity and cruelty. If it has affected that part which is subject to desire, it will be the parent of gluttony, fornication, covetousness, avarice, and noxious and earthly desires.