Faculty-of-desire

Is it any explanation to say that desire is vested in a Faculty-of-desire and anger in the Irascible-Faculty and, collectively, that all tendency is seated in the Appetitive-Faculty? Such a statement of the facts does not help towards making the affections common to the Couplement; they might still be seated either in the Soul alone or in the body alone. On the one hand if the appetite is to be stirred, as in the carnal passion, there must be a heating of the blood and the bile, a well-defined state of the body; on the other hand, the impulse towards The Good cannot be a joint affection, but, like certain others too, it would belong necessarily to the Soul alone. Enneads: I. I. 5