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.

The most dangerous untruths are truths slightly distorted.

Sickness is mankind's greatest defect.

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.

To grow wiser means to learn to know better and better the faults to which this instrument with which we feel and judge can be subject.

Do not judge God's world from your own. Trim your own hedge as you wish and plant your flowers in the patterns you can understand, but do not judge the garden of nature from your little window box.

Man is a masterpiece of creation if for no other reason than that, all the weight of evidence for determinism notwithstanding, he believes he has free will.