But of Pleasure the whole nature is complete at any given moment: it is plain then that Pleasure and Movement must be different from one another, and that Pleasure belongs to the class of things whole and complete. And this might appear also from the impossibility of moving except in a definite time, whereas there is none with respect to the sensation of Pleasure, for what exists at the very present moment is a kind of “whole.” From these considerations then it is plain that people are not warranted in saying that Pleasure is a Movement or a Generation: because these terms are not applicable to all things, only to such as are divisible and not “wholes:” I mean that of an act of Sight there is no Generation, nor is there of a point, nor of a monad, nor is any one of these a Movement or a Generation: neither then of Pleasure is there Movement or Generation, because it is, as one may say, “a whole.”[11] Chapter IV. Now since every Percipient Faculty works upon the Object answering to it, and perfectly the Faculty in a good state upon the most excellent of the Objects within its range (for Perfect Working is thought to be much what I have described; and we will not raise any question about saying “the Faculty” works, instead of, “that subject wherein the Faculty resides”), in each case the best Working is that of the Faculty in its best state upon the best of the Objects answering to it. And this will be, further, most perfect and most pleasant: for Pleasure is attendant upon every Percipient Faculty, and in like manner on every intellectual operation and speculation; and that is most pleasant which is most perfect, and that most perfect which is the Working of the best Faculty upon the most excellent of the Objects within its range. And Pleasure perfects the Working. But Pleasure does not perfect it in the same way as the Faculty and Object of Perception do, being good; just as health and the physician are not in similar senses causes of a healthy state. And that Pleasure does arise upon the exercise of every 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: 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.