I did not, however, commit suicide, because I wished to know more of mathematics.

I like mathematics because it is not human and has nothing particular to do with this planet or with the whole accidental universe - because, like Spinoza's God, it won't love us in return.

Through the greatness of the universe, which philosophy contemplates, the mind also is rendered great, and becomes capable of that union with the universe which constitutes its highest good.

Experience has taught me a technique for dealing with such people [...] I counter the devotees of the Great Pyramid by adoration of the Sphinx; and the devotee of nuts by pointing out that hazelnuts and walnuts are as deleterious as other foods and only Brazil nuts should be tolerated. But when I was younger I had not yet acquired this technique, with the result that my contacts with cranks were sometimes alarming.

Every living thing is a sort of imperialist, seeking to transform as much as possible of its environment into itself.

Science has made unrestricted national sovereignty incompatible with human survival. The only possibilities are now world government or death.

The human heart as modern civilization has made it is more prone to hatred than to friendship. And it is prone to hatred because it is dissatisfied.