And, further, the pleasure completes the exercise of the faculty. But the pleasure completes it in a different way from that in which the object and the faculty of sense complete it, when both are as they should be; just as health causes healthy activities in a different way from that in which the physician causes them.

(That the exercise of every sense is accompanied by pleasure is evident: we speak of pleasant sights and pleasant sounds.

It is evident also that the pleasure is greatest when both the faculty and that upon which it is exercised are as good as they can be: when this is the case both with the object of sense and the sentient subject, there will always be pleasure, so long, that is, as you have the subject to act and the object to be acted upon.)

Now, the pleasure makes the exercise complete not as the habit or trained faculty 248 does, being already present in the subject, but as a sort of superadded completeness, like the grace of youth. 249