Virtue is a habit of the mind, consistent with nature and moderation and reason.

True law is right reason in agreement with nature;...it summons to duty by its commands, and averts from wrongdoing by its prohibitions... It is a sin to try to alter this law, nor is it allowable to attempt to repeal any part of it, and it is impossible to abolish it entirely.

Let every man practise the trade which he best understands.

As I give thought to the matter, I find four causes for the apparent misery of old age; first, it withdraws us from active accomplishments; second, it renders the body less powerful; third, it deprives us of almost all forms of enjoyment; fourth, it stands not far from death.

Nothing troubles you for which you do not yearn.

Friendship is the only point in human affairs concerning the benefit of which all, with one voice, agree.

When a government becomes powerful it is destructive, extravagant and violent; it is an usurer which takes bread from innocent mouths and deprives honorable men of their substance, for votes with which to perpetuate itself.