The only question which any wise man can ask himself, and which any honest man will ask himself, is whether a doctrine is true or false.

The chess-board is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us.

Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.

I do not say think as I think, but think in my way. Fear no shadows, least of all in that great spectre of personal unhappiness which binds half the world to orthodoxy.

The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land, to add something to the extent and the solidity of our possessions.

The child who has been taught to make an accurate elevation, plan, and section of a pint pot has had an admirable training in accuracy of eye and hand.

Life is like walking along a crowded street--there always seem to be fewer obstacles to getting along on the opposite pavement--and yet, if one crosses over, matters are rarely mended.