Pleasure in the job puts perfection in the work.

The energy of the mind is the essence of life.

At his best, man is the noblest of all animals; separated from law and justice he is the worst.

Happiness depends upon ourselves.

My best friend is the man who in wishing me well wishes it for my sake.

You will never do anything in this world without courage. It is the greatest quality of the mind next to honor.

In all things of nature there is something of the marvelous.

There is no great genius without a mixture of madness.

Quality is not an act, it is a habit.

Friendship is a single soul dwelling in two bodies.