The only question which any wise man can ask himself, and which any honest man will ask himself, is whether a doctrine is true or false.

People may talk about intellectual teaching, but what we principally want is the moral teaching.

I am content with nothing, restless and ambitious... and I despise myself for the vanity, which formed half the stimulus to my exertions. Oh would that I were one of those plodding wise fools who having once set their hand to the plough go on nothing doubting.

The only question which any wise man can ask himself, and which any honest man will ask himself, is whether a doctrine is true or false.

Proclaim human equality as loudly as you like, Witless will serve his brother.

Science is nothing, but trained and organized common sense.

If then, said I, the question is put to me would I rather have a miserable ape for a grandfather or a man highly endowed by nature and possessing great means and influence and yet who employs those faculties for the mere purpose of introducing ridicule into a grave scientific discussion-I unhesitatingly affirm my preference for the ape.