Complete prohibition of all chemical mind changers can be decreed, but cannot be enforced, and tends to create more evils than it cures.

The inconveniences and horrors of the pox are perfectly well known to every one; but still the disease flourishes and spreads. Several million people were killed in a recent war and half the world ruined; but we all busily go on in courses that make another event of the same sort inevitable. Experientia docet? Experientia doesn't.

If one's different, one's bound to be lonely.

Some of the greatest advances in mathematics have been due to the invention of symbols, which it afterwards became necessary to explain; from the minus sign proceeded the whole theory of negative quantities.

Most of one's life is one prolonged effort to prevent oneself thinking.

The most intractable of our experiences is the experience of Time-the intuition of duration, combined with the thought of perpetual perishing.

Assembled in a crowd, people lose their powers of reasoning and their capacity for moral choice.