Fraud and falsehood only dread examination. Truth invites it.

Everything that enlarges the sphere of human powers, that shows man he can do what he thought he could not do, is valuable.

If, sir, men were all virtuous, I should with great alacrity teach them all to fly. But what would be the security of the good if the bad could at pleasure invade them from the sky? Against an army sailing through the clouds neither wall, nor mountains, nor seas could afford any security.

The faults of a man loved or honoured sometimes steal secretly and imperceptibly upon the wise and virtuous, but by injudicious fondness or thoughtless vanity are adopted with design.

Men who cannot deceive others are very often successful at deceiving themselves.

No member of a society has a right to teach any doctrine contrary to what the society holds to be true.

He who endeavors to please must appear pleased.