The firmest of friendships have been formed in mutual adversity, as iron is most strongly united by the fiercest flame.

Metaphysicians have been learning their lessons for the last four thousand years, and it is high time that they should now begin to teach us something. Can any of the tribe inform us why all the operations of the mind are carried on with undiminished strength and activity in dreams, except the judgment, which alone is suspended and dormant?

To know the pains of power, we must go to those who have it; to know its pleasures, we must go to those who are seeking it: the pains of power are real, its pleasures imaginary.

The intoxication of anger, like that of the grape, shows us to others, but hides us from ourselves.

Doubt is the vestibule through which all must pass before they can enter into the temple of wisdom.

Nothing is more durable than the dynasty of Doubt; for he reigns in the hearts of all his people, but gives satisfaction to none of them, and yet he is the only despot who can never die, while any of his subjects live.

He that knows himself, knows others; and he that is ignorant of himself, could not write a very profound lecture on other men's heads.