We feel surprise when travellers tell us of the vast dimensions of the Pyramids and other great ruins, but how utterly insignificant are the greatest of these, when compared to these mountains of stone accumulated by the agency of various minute and tender animals!

we are always slow in admitting any great change of which we do not see the intermediate steps

Life is nearly over with me. I have taken no pains about my style of writing.

Free will is to mind what chance is to matter.

Great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure.

A mathematician is a blind man in a dark room looking for a black cat which isn't there.

I was a young man with uninformed ideas. I threw out queries, suggestions, wondering all the time over everything; and to my astonishment the ideas took like wildfire. People made a religion of them.