Plotinos: Complete Works, v. 2 In Chronological Order,...

Must we attribute sensation to each power, but in a different manner? In this case, for instance, it will be sight, and not appetite, which will perceive sense-objects; but appetite will be later wakened by sensation which will be "relayed," (as the Stoics would say); and though it does not judge of sensation, it will unconsciously feel the characteristic affection. The same state of affairs will obtain with anger. It will be sight which will show us an injustice, but it will be anger which will resent it. Just so, when a shepherd notices a wolf near his flock, the dog, though he have not yet observed anything, will be excited by the smell or noise of the wolf. It certainly is appetite which experiences pleasure, and which keeps a trace of it; but this trace constitutes an affection or disposition, and not a memory. It is another power which observes the enjoyment of pleasure, and which remembers what occurred. This is proved by the fact that memory is often ignorant of the things in which appetite has participated, though appetite still preserve traces thereof.