Then not only custom, but also nature affirms that to do is more disgraceful than to suffer injustice, and that justice is equality.

The essence of knowledge is self-knowledge.

The most important part of education is right training in the nursery. The soul of the child in his play should be trained to that sort of excellence in which, when he grows to manhood, he will have to be perfected.

Mathematics is the language in which the gods talk to people.

From a short-sided view, the whole moving contents of the heavens seemed to them a parcel of stones, earth and other soul-less bodies, though they furnish the sources of the world order.

The only thing worse than suffering an injustice is committing an injustice.

We are bound to our bodies like an oyster to its shell.