Philosophy is true mother of the arts [of science].

Nor do I regret that I have lived, since I have so lived that I think I was not born in vain, and I quit life as if it were an inn, not a home.

In all great arts, as in trees, it is the height that charms us; we care nothing for the roots or trunks, yet it could not be without the aid of these.

It is the soul itself which sees and hears, and not those parts which are, as it were, but windows to the soul.

It is virtue, virtue, which both creates and preserves friendship. On it depends harmony of interest, permanence, fidelity.

Nothing is so difficult to believe that oratory cannot make it acceptable, nothing so rough and uncultured as not to gain brilliance and refinement from eloquence.

Of all nature's gifts to the human race, what is sweeter to a man than his children?