To be able to fill leisure intelligently is the last product of civilization, and at present very few people have reached this level.
Change is scientific, progress is ethical; change is indubitable, whereas progress is a matter of controversy.
All exact science is dominated by the idea of approximation.
Freedom of opinion can only exist when the government thinks itself secure.
Order, unity and continuity are human inventions just as truly as catalogues and encyclopedias.
The human race may well become extinct before the end of the century.
Even in civilized mankind faint traces of monogamous instincts can be perceived.
The infliction of cruelty with a good conscience is a delight to moralists - that is why they invented hell.
Obscenity is what happens to shock some elderly and ignorant magistrate.
Life is nothing but a competition to be the criminal rather than the victim.