For contemplation is both the highest form of activity (since the intellect is the highest thing in us, and the objects that it apprehends are the highest things that can be known), and also it is the most continuous, because we are more capable of continuous contemplation than we are of any practical activity.
A government which is composed of the middle class more nearly approximates to democracy than to oligarchy, and is the safest of the imperfect forms of government.
The male has more teeth than the female in mankind, and sheep and goats, and swine. This has not been observed in other animals. Those persons which have the greatest number of teeth are the longest lived; those which have them widely separated, smaller, and more scattered, are generally more short lived.
Everything necessarily is or is not, and will be or will not be; but one cannot divide and say that one or the other is necessary.I mean, for example: it is necessary for there to be or not to be a sea-battle tomorrow; but it is not necessary for a sea-battle to take place tomorrow, or for one not to take place--though it is necessary for one to take place or not to take place.
Since we think we understand when we know the explanation, and there are four types of explanation (one, what it is to be a thing; one, that if certain things hold it is necessary that this does; another, what initiated the change; and fourth, the aim), all these are proved through the middle term.
If there is some end of the things we do, which we desire for its own sake, clearly this must be the good. Will not knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what we should? If so, we must try, in outline at least, to determine what it is.