[3] Again, (c) why should not pleasure be like health, which is definite although it admits of degrees? For health is not constituted by the same proportion of elements in all persons; nor yet by one particular proportion in the same person always, but when it is in process of dissolution it still lasts for a certain time, and therefore it varies in degree. It is possible therefore that the same may be the case with pleasure.
[4] Again, they postulate2 that the Good is perfect, whereas a motion or process of generation is imperfect, and then they attempt to prove that pleasure is a motion or process. This appears to be a mistake. (a) It would seem that pleasure is not a motion; for we hold it to be a property of all motion to be quick or slow—if (as with the motion3 of the firmament) not absolutely, then relatively to some other moving body. But pleasure possesses neither absolute nor relative velocity. You can become pleased quickly, just as you can get angry quickly: