[T]he good for man is an activity of the soul in accordance with virtue, or if there are more kinds of virtue than one, in accordance with the best and most perfect kind.
This quotation from Book I, Chapter 7, connects Aristotle’s conception of happiness and the good life with his conception of virtue. We should observe first that “the good for man is an activity.” The word activity translates from the Greek energeia, which signifies not only physical activity but also mental activity as seemingly inactive as contemplation or daydreaming. The point is that the good life is not an end state that we achieve but rather a way of life that we live. We might consider the cliché “life is a journey, not a destination” to convey some sense of the distinction Aristotle has in mind.
The bulk of the Ethics is devoted to discussing the various moral and intellectual virtues. These virtues are dispositions to behave in the correct way. They are not themselves activities, but they ensure that our activities will be of the right kind. To live “in accordance with virtue,” then, is to live in such a way that our activities flow naturally from a virtuous disposition.
In Books VI and X, Aristotle suggests that the intellectual virtue of wisdom is the “best and most perfect kind” of virtue, and he ultimately concludes that the good for man is rational contemplation in accordance with the intellectual virtue of wisdom.