How we cite our quotes: (Book.Chapter.Bekker #s); all Bekker line numbers are approximate, since they are keyed to the original Greek.
Quote #10
Pleasure also completes the activities, as indeed it does in being alive, which people long for. It is reasonable, then, that they aim also at pleasure, since it completes for each what it is to be alive, which is a choiceworthy thing. (10.4.1175a16-17)
Aristotle's trying to convince us that pleasure may be the premier good thing about being alive. And he's doing a pretty good job of it. He says that life itself is a kind of activity within which we choose other activities that accord with our virtues. While each of these activities are good in themselves, they are made even better by pleasure.
Pleasure, then, completes human activity, which means that a clever human being might, in fact, be doing the things he does specifically because pleasure is the end he's aiming for from the beginning.