We have thus shown that Happiness consists in exercise or actual living according to excellence; naturally, therefore, according to the highest excellence, or the excellence of the best part of man. This best part is the Intellect (_Nous_), our most divine and commanding element; in its exercise, which is theoretical or speculative, having respect to matters honourable, divine, and most worthy of study. Such philosophical exercise, besides being the highest function of our nature, is at the same time more susceptible than any mode of active effort, of being prosecuted for a long continuance. It affords the purest and most lasting pleasure; it approaches most nearly to being self-sufficing, since it postulates little more than the necessaries of life, and is even independent of society, though better _with_ society. Perfect happiness would thus be the exercise of the theorizing intellect, continued through a full period of life. But this is more than we can expect. Still, we ought to make every effort to live according to this best element of our nature; for, though small in bulk, it stands exalted above the rest in power and dignity, and, being the sovereign element in man, is really The Man himself (VII.). Next, yet only second, come the other branches of excellence: the active social life of a good citizen. Exercises according to this branch of virtue are the natural business of man, for it is bound up with our whole nature, including body as well as mind, our appetites, and our passions, whereas the happiness of intellect is separate. Active social virtue postulates conditions of society and external aids in considerable measure; but the life of intellect requires only the minimum of these, and is even impeded by much of them.