Leisure of itself gives pleasure and happiness and enjoyment of life, which are experienced, not by the busy man, but by those who have leisure.

Beauty depends on size as well as symmetry. No very small animal can be beautiful, for looking at it takes so small a portion of time that the impression of it will be confused. Nor can any very large one, for a whole view of it cannot be had at once, and so there will be no unity and completeness.

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.

It is clear that there is some difference between ends: some ends are energeia [energy], while others are products which are additional to the energeia.

We must not feel a childish disgust at the investigations of the meaner animals. For there is something marvelous in all natural things.

All men desire by nature to know.

The best way to avoid envy is to deserve the success you get.