Marriage is for women the commonest mode of livelihood, and the total amount of undesired sex endured by women is probably greater in marriage than in prostitution.

Unrestricted nationalism is, in the long run, incompatible with world peace.

Machines deprive us of two things which are certainly important ingredients of human happiness, namely, spontaneity and variety.

One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision.

As soon as we abandon our own reason, and are content to rely upon authority, there is no end to our troubles.

I suggest to young professors that their first work should be written in a jargon only to be understood by the erudite few. With that behind them, they can ever after say what they have to say in a language 'understand of the people.'

Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.