Scepticism, that dry caries of the intelligence.

Human intelligence discovered a way of perpetuating itself, one not only more durable and more resistant than architecture, but also simpler and easier.

Reason is intelligence taking exercise. Imagination is intelligence with an erection.

Intelligence is the wife, imagination is the mistress, memory is the servant.

Let no one misunderstand our idea; we do not confound what are called 'political opinions' with that grand aspiration after progress with that sublime patriotic, democratic, and human faith, which, in our days, should be the very foundation of all generous intelligence.

Thought is more than a right - it is the very breath of man. Whoever fetters thought attacks man himself. To speak, to write, to publish, are things, so far as the right is concerned, absolutely identical. They are the ever-enlarging circles of intelligence in action; they are the sonorous waves of thought.