To see every day how people get the name 'genius' just as the wood-lice in the cellar the name 'millipede'-not because they have that many feet, but because most people don't want to count to 14-this has had the result that I don't believe anyone any more without checking.

Nothing is more conducive to peace of mind than not having any opinion at all.

People who never have any time on their hands are those who do the least.

People who have read a good deal rarely make great discoveries. I do not say this in excuse of laziness, but because invention presupposes an extensive independent contemplation of things.

Above all things expand the frontiers of science: without this the rest counts for nothing.

I have remarked very clearly that I am often of one opinion when I am lying down and of another when I am standing up.

There is no more important rule of conduct in the world than this: attach yourself as much as you can to people who are abler than you and yet not so very different that you cannot understand them.