Human nature: vindictiveness lightly coated with dishonesty. - Celia Green

The human race has to be bad at psychology; if it were not, it would understand why it is bad at everything else.

It is actually a principle of modern paternalism that if you want something you should be stopped from having it[…] Most foods are harmful to some people if taken in excess, and I expect the only reason that carrots are still available without a prescription is that no one has got very excited about them, or claimed that they might cure cancer.

The way to do research is to attack the facts at the point of greatest astonishment.