Many secrets of art and nature are thought by the unlearned to be magical.

It's not what we profess but what we practice that gives us integrity.

There is as much difference between the counsel that a friend giveth, and that a man giveth himself, as there is between the counsel of a friend and of a flatterer. For there is no such flatterer as is a man's self.

But by far the greatest obstacle to the progress of science and to the undertaking of new tasks and provinces therein is found in this-that men despair and think things impossible.

Man prefers to believe what he prefers to be true.

Nor is mine a trumpet which summons and excites men to cut each other to pieces with mutual contradictions, or to quarrel and fight with one another; but rather to make peace between themselves, and turning with united forces against the Nature of Things

In all superstition wise men follow fools.