A human being in perfection ought always to preserve a calm and peaceful mind and never to allow passion or a transitory desire to disturb his tranquility.

Nothing contributes so much to tranquilize the mind as a steady purpose - a point on which the soul may fix its intellectual eye.

It is true, we shall be monsters, cut off from all the world; but on that account we shall be more attached to one another.

Seek happiness in tranquility and avoid ambition even if it be only the apparently innocent one of distinguishing yourself in science and discoveries.

From my infancy I was imbued with high hopes and a lofty ambition.

Man," I cried, "how ignorant art thou in thy pride of wisdom!

...learn from my miseries, and do not seek to increase your own.