I consider the official Catholic attitude on divorce, birth control, and censorship exceedingly dangerous to mankind.

A good social system is not to be secured by making people unselfish, but, by making their own vital impulses fit in with other peoples. This is feasible. Those who have produced stoic philosophies have all had enough to eat and drink. I feel I shall find the truth on my deathbed and be surrounded by people too stupid to understand—fussing about medicines instead of searching for wisdom. I hate being all tidy like a book in a library where nobody reads – prison is horribly like that.

None but a coward dares to boast that he has never known fear.

No satisfaction based upon self-deception is solid.

I am delighted to know that Principia Mathematica can now be done by machinery. . . I am quite willing to believe that anything in deductive logic can be done by machinery.

I cannot favour laws such as that of Idaho, which allows sterilization of 'mental defectives, epileptics, habitual criminals, moral degenerates, and sex perverts.' The last two categories here are very vague . . . The law of Idaho would have justified the sterilization of Socrates, Plato, Julius Caesar, and St. Paul.

When you are studying any matter or considering any philosophy, ask yourself only: what are the facts, and what is the truth that the facts bear out. Never let yourself be diverted by what you wish to believe, but look only and surely at what are the facts.