Everything that is hard to attain is easily assailed by the generality of men.

The heaven is spherical in shape, and moves as a sphere; the earth too is sensibly spherical in shape, when taken as a whole; in position it lies in the middle of the heavens very much like its center; in size and distance it has the ratio of a point to the sphere of the fixed stars; and it has no motion from place to place.

I know that I am mortal and the creature of a day; but when I search out the massed wheeling circles of the stars, my feet no longer touch the earth, but, side by side with Zeus himself, I take my fill of ambrosia, the food of the gods.

There are three classes of friendship and enmity, since men are so disposed to one another either by preference or by need or by pleasure and pain.

It is clearly evident that most events of a widespread nature draw their causes from the enveloping heavens.

The length of life takes the leading place among inquiries about events following birth.

As material fortune is associated with the properties of the body, so honor belongs to those of the soul.