If you want to be miserable, think about yourself, about what you want, what you like, what respect people ought to pay you and what people think of you.

You must not say that this cannot be, or that that is contrary to nature. You do not know what Nature is, or what she can do; and nobody knows; not even Sir Roderick Murchison, or Professor Huxley, or Mr. Darwin, or Professor Faraday, or Mr. Grove, or any other of the great men whom good boys are taught to respect. They are very wise men; and you must listen respectfully to all they say: but even if they should say, which I am sure they never would, 'That cannot exist. That is contrary to nature,' you must wait a little, and see; for perhaps even they may be wrong.

If I am ever obscure in my expressions, do not fancy that therefore I am deep. If I were really deep, all the world would understand, though they might not appreciate. The perfectly popular style is the perfectly scientific one. To me an obscurity is a reason for suspecting a fallacy.

I am not aware that payment, or even favors, however gracious, bind any man's soul and conscience in questions of highest morality and highest importance.

Truth, for its own sake, had never been a virtue with the Roman clergy.

Friendship is like a glass ornament, once it is broken it can rarely be put back together exactly the same way.

If "ifs" and "ands" were pots and pans, there'd be no work for tinkers' hands