The proof that you know something is that you are able to teach it

The student of politics therefore as well as the psychologist must study the nature of the soul.

Metaphysics involves intuitive knowledge of unprovable starting-points concepts and truth and demonstrative knowledge of what follows from them.

The least deviation from truth will be multiplied later.

To learn is a natural pleasure, not confined to philosophers, but common to all men.

Today, see if you can stretch your heart and expand your love so that it touches not only those to whom you can give it easily, but also to those who need it so much.

Greatness of spirit is to bear finely both good fourtune and bad, honor and disgrace, and not to think highly of luxury or attention or power or victories in contests, and to possess a certain depth and magnitude of spirit.