Percipient Faculty is evident, for we commonly say that sights and sounds are pleasant; it is plain also that this is especially the case when the Faculty is most excellent and works upon a similar Object: and when both the Object and Faculty of Perception are such, Pleasure will always exist, supposing of course an agent and a patient.
Furthermore, Pleasure perfects the act of Working not in the way of an inherent state but as a supervening finish, such as is bloom in people at their prime. Therefore so long as the Object of intellectual or sensitive Perception is such as it should be and also the Faculty which discerns or realises the Object, there will be Pleasure in the Working: 1175a because when that which has the capacity of being acted on and that which is apt to act are alike and similarly related, the same result follows naturally.
How is it then that no one feels Pleasure continuously? is it not that he wearies, because all human faculties are incapable of unintermitting exertion; and so, of course, Pleasure does not arise either, because that follows upon the act of Working. But there are some things which please when new, but afterwards not in the like way, for exactly the same reason: that at first the mind is roused and works on these Objects with its powers at full tension; just as they who are gazing stedfastly at anything; but afterwards the act of Working is not of the kind it was at first, but careless, and so the Pleasure too is dulled.
Again, a person may conclude that all men grasp at Pleasure, because all aim likewise at Life and Life is an act of Working, and every man works at and with those things which also he best likes; the musical man, for instance, works with his hearing at music; the studious man with his intellect at speculative questions, and so forth. And Pleasure perfects the acts of Working, and so Life after which men grasp. No wonder then that they aim also at Pleasure, because to each it perfects Life, which is itself choiceworthy. (We will take leave to omit the question whether we choose Life for
