What would become of the garden if the gardener treated all the weeds and slugs and birds and trespassers as he would like to be treated, if he were in their place?

Unity of plan everywhere lies hidden under the mask: of diversity of structure-the complex is everywhere evolved out of the simple.

I conceive that the leading characteristic of the nineteenth century has been the rapid growth of the scientific spirit, the consequent application of scientific methods of investigation to all the problems with which the human mind is occupied, and the correlative rejection of traditional beliefs which have proved their incompetence to bear such investigation.

The best men of the best epochs are simply those who make the fewest blunders and commit the fewest sins.

Science is simply common sense at its best.

If every man possessed everything he wanted, and no one had the power to interfere with such possession; or if no man desired thatwhich could damage his fellow-man, justice would have no part to play in the universe.

All knowledge is good. It is impossible to say any fragment of knowledge, however insignificant or remote from one's ordinary pursuits, may not some day be turned to account.