The Good of man is the active exercise of his soul's faculties in conformity with excellence or virtue, or if there be several human excellences or virtues, in conformity with the best and most perfect among them.

The vigorous are no better than the lazy during one half of life, for all men are alike when asleep.

Let us be well persuaded that everyone of us possesses happiness in proportion to his virtue and wisdom, and according as he acts in obedience to their suggestion.

Metaphysics involves intuitive knowledge of unprovable starting-points concepts and truth and demonstrative knowledge of what follows from them.

Suppose, then, that all men were sick or deranged, save one or two of them who were healthy and of right mind. It would then be the latter two who would be thought to be sick and deranged and the former not!

That which is impossible and probable is better than that which is possible and improbable.

The intelligence consists not only in the knowledge but also in the skill to apply the knowledge into practice.