The first essential responsibility of the state is control of the market-place: there must be some official charged with the duty of seeing that honest dealing and good order prevail. For one of the well-nigh essential activities of all states is the buying and selling of goods to meet their mutual basic needs; this is the quickest way to self-sufficiency, which seems to be what moves men to combine under a single constitution.

All that we do is done with an eye to something else.

The excellence of a thing is related to its proper function.

Xenophanes states that the fire in Lipara once failed for sixteen years, but returned in the seventeenth year. They say that the lava-stream in Etna is neither flaming nor continuous, but returns only after an interval of many years.

There is more both of beauty and of raison d'etre in the works of nature- than in those of art.

Governments which have a regard to the common interest are constituted in accordance with strict principles of justice, and are therefore true forms; but those which regard only the interest of the rulers are all defective and perverted forms, for they are despotic, whereas a state is a community of freemen.

Metaphysics is universal and is exclusively concerned with primary substance. ... And here we will have the science to study that which is, both in its essence and in the properties which it has.