There is no worse tyranny than to force a man to pay for what he does not want merely because you think it would be good for him.

But space travel can't ease the pressure on a planet grown too crowded not even with today's ships and probably not with any future ships-because stupid people won't leave the slopes of their home volcano even when it starts to smoke and rumble. What space travel does do is drain off the best brains: those smart enough to see a catastrophe before it happens, and with the guts to pay the price-abandon home, wealth, friends, relatives, everything-and go. That's a tiny fraction of one percent. But that's enough.

Audacity, always audacity - soundest principal of strategy.

Thinking doesn't pay. Just makes you discontented with what you see around you.

It seems to me that the secret of true happiness in life is to know what you are and then be content to be that, in style, head up and proud, and not yearn to be something else.

Anyone who can worship a trinity and insist that his religion is a monotheism can believe anything.

The most expensive thing in the world is a second-best military establishment, good but not good enough to win.