[Prudence] is the virtue of that part of the intellect [the calculative] to which it belongs; and . . . our choice of actions will not be right without Prudence any more than without Moral Virtue, since, while Moral Virtue enables us to achieve the end, Prudence makes us adopt the right means to the end.
Whether if soul did not exist time would exist or not, is a question that may fairly be asked; for if there cannot be someone to count there cannot be anything that can be counted, so that evidently there cannot be number; for number is either what has been, or what can be, counted.
Property should be in a general sense common, but as a general rule private... In well-ordered states, although every man has his own property, some things he will place at the disposal of his friends, while of others he shares the use of them.
Now, the causes being four, it is the business of the student of nature to know about them all, and if he refers his problems back to all of them, he will assign the "why" in the way proper to his science-the matter, the form, the mover, that for the sake of which.
Actual knowledge is identical with its object: in the individual, potential knowledge is in time prior to actual knowledge, but in the universe as a whole it is not prior even in time. Mind is not at one time knowing and at another not. When mind is set free from its present conditions it appears as just what it is and nothing more: this alone is immortal and eternal (we do not, however, remember its former activity because, while mind in this sense is impassible, mind as passive is destructible), and without it nothing thinks.