We know the effects of many things, but the cause of few; experience, therefore, is a surer guide than imagination, and inquiry than conjecture.

It is with nations as with individuals, those who know the least of others think the highest of themselves; for the whole family of pride and ignorance are incestuous, and mutually beget each other.

Men of strong minds and who think for themselves, should not be discouraged on finding occasionally that some of their best ideas have been anticipated by former writers; they will neither anathematize others nor despair themselves. They will rather go on discovering things before discovered, until they are rewarded with a land hitherto unknown, an empire indisputably their own, both right of conquest and of discovery.

Habit will reconcile us to everything but change

The greatest friend of truth is Time, her greatest enemy is Prejudice, and her constant companion is Humility.

Precisely in proportion to our own intellectual weakness will be our credulity as to those mysterious powers assumed by others.

It is almost as difficult to make a man unlearn his errors as his knowledge.