When people talk of atoms obeying fixed laws, they are either ascribing some kind of intelligence and free will to atoms or they are talking nonsense. There is no obedience unless there is at any rate a potentiality of disobeying.

An obstinate man does not hold opinions, but they hold him; for when he is once possessed with an error, it is, like a devil, only cast out with great difficulty.

Friends are like money, easier made than kept.

They say the test of [literary power] is whether a man can write an inscription. I say, "Can he name a kitten?" And by this test I am condemned, for I cannot.

Science is being daily more and more personified and anthromorphized into a god. By and by they will say that science took our nature upon him, and sent down his only begotten son, Charles Darwin, or Huxley, into the world so that those who believe in him, &c.; and they will burn people for saying that science, after all, is only an expression for our ignorance of our own ignorance.

All animals, except man, know that the principal business of life is to enjoy it - and they do enjoy it as much as man and other circumstances will allow.

You cannot have a thing "matter" by itself which shall have no motion in it, nor yet a thing "motion" by itself which shall exist apart from matter; you must have both or neither. You can have matter moving much, or little, and in all conceivable ways; but you cannot have matter without any motion more than you can have motion without any matter that is moving.