Secrecy begets tyranny.

Morals - all correct moral laws - derive from the instinct to survive. Moral behavior is survival behavior above the individual level.

Happiness consists in getting enough sleep. Just that, nothing more.

A handy short definition of almost all science fiction might read: realistic speculation about possible future events, based solidly on adequate knowledge of the real world, past and present, and on a thorough understanding of the nature and significance of the scientific method.

When one teaches, two learn.

Revolution is an art that I pursue rather than a goal I expect to achieve. Nor is this a source of dismay; a lost cause can be as spiritually satisfying as a victory.

An armed man need not fight.