Belief in the causal nexus is superstition.

It would strike me as ridiculous to want to doubt the existence of Napoleon; but if someone doubted the existence of the earth 150years ago, perhaps I should be more willing to listen, for now he is doubting our whole system of evidence.

A man will be imprisoned in a room with a door that's unlocked and opens inwards; as long as it does not occur to him to pull rather than push it.

My attitude towards him is an attitude towards a soul. I am not of the opinion that he has a soul. . . .

That the world is, is the mystical.

I won't say 'See you tomorrow' because that would be like predicting the future, and I'm pretty sure I can't do that.

This is how philosophers should salute each other: ‘Take your time.