Friendship improves happiness, and abates misery, by doubling our joys, and dividing our grief.

Six mistakes mankind keeps making century after century:
- Believing that personal gain is made by crushing others;
- Worrying about things that cannot be changed or corrected;
- Insisting that a thing is impossible because we cannot accomplish it;
- Refusing to set aside trivial preferences;
- Neglecting development and refinement of the mind;
- Attempting to compel others to believe and live as we do.

Gratitude is not only the greatest of virtues, but the parent of all others.

The pursuit, even of the best things, ought to be calm and tranquil.

A room without books is like a body without a soul.