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.
The Life of the intellect is the best and pleasantest for man, because the intellect more than anything else is the man. Thus it will be the happiest life as well.
Moral virtue is ... a mean between two vices, that of excess and that of defect, and ... it is no small task to hit the mean in each case, as it is not, for example, any chance comer, but only the geometer, who can find the center of a given circle.
We ought to be able to persuade on opposite sides of a question; as also we ought in the case of arguing by syllogism: not that we should practice both, for it is not right to persuade to what is bad; but in order that the bearing of the case may not escape us, and that when another makes an unfair use of these reasonings, we may be able to solve them.
All three states - the Lacedaemonian, the Cretan, and the Carthaginian - nearly resemble one another, and are very different from any others. Many of the Carthaginian institutions are excellent. The superiority of their constitution is proved by the fact that the common people remains loyal to the constitution; the Carthaginians have never had any rebellion worth speaking of, and have never been under the rule of a tyrant.
The trade of the petty usurer is hated with most reason: it makes a profit from currency itself, instead of making it from the process which currency was meant to serve. Their common characteristic is obviously their sordid avarice.