The great tragedy of Science - the slaying of a beautiful hypothesis by an ugly fact.

M. Comte's philosophy, in practice, might be compendiously described as Catholicism minus Christianity.

If some great Power would agree to make me always think what is true and do what is right, on condition of being turned into a sort of clock and wound up every…

The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, scepticism is the highest of duties; blind faith the one unpar…

Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experimen…

I cannot believe - and I say this with all the emphasis of which I am capable - that there can ever be any good excuse for refusing to face the evidence in fav…

If somebody believes that the world is only (...) a few thousand years old, when the true age of the Earth is of the order of a few billion years old, that mea…