An arch consists of two weaknesses which, leaning one against the other, make a strength.

Experience never misleads; what you are misled by is only your judgment, and this misleads you by anticipating results from experience of a kind that is not produced by your experiments.

While you are alone you are entirely your own master and if you have one companion you are but half your own, and the less so in proportion to the indiscretion of his behavior.

One day the world will look upon research upon animals as it now looks upon research on human beings.

A man was desired to rise from bed because the sun was already up. He replied: "If I had as far to go and as much to do as he has, I should be up by now; but having but a little way to go, I shall not get up yet."

Not to anticipate is already to moan.

I woke up only to find the rest of the world asleep.