Few people can be happy unless they hate some other person, nation, or creed.

Beware the man of the single book

Science does not aim at establishing immutable truths and eternal dogmas; its aim is to approach the truth by successive approximations, without claiming that at any stage final and complete accuracy has been achieved.

All the conditions of happiness are realized in the life of the man of science.

[Regarding] the convention that clergymen are more virtuous than other men. Any average selection of mankind, set apart and told that it excels the rest in virtue, must tend to sink below the average.

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.

The puritanism of Christianity has played havoc with the moderation that an enlightened and tolerant critical spirit would have produced. I've noticed that in whatever country, county, town, or other region there is a regulation enjoining temperance, the population seems to be entirely composed of teetotallers and drunkards. There's a Bible on that shelf there. But I keep it next to Voltaire - poison and antidote.