What you have to learn to do, you learn by doing.

While most of those who hold that the whole heaven is finite say that the earth lies at the center, the philosophers of Italy, the so-called Pythagoreans, assert the contrary. They say that in the middle there is fire, and that the earth is one of the stars, and by its circular motion round the center produces night and day.

Now property is part of a household, and the acquisition of property part of household-management; for neither life itself nor the good life is possible without a certain minimum supply of the necessities.

The heart is the perfection of the whole organism. Therefore the principles of the power of perception and the souls ability to nourish itself must lie in the heart.

...in this way the structure of the universe- I mean, of the heavens and the earth and the whole world- was arranged by one harmony through the blending of the most opposite principles.

It is the mark of an educated mind to expect that amount of exactness which the nature of the particular subject admits. It is equally unreasonable to accept merely probable conclusions from a mathematician and to demand strict demonstration from an orator.

That in the soul which is called the mind is, before it thinks, not actually any real thing.