I gave up my dream of flight and rebirth, and invented a proverb to fit the occasion: he who produces an illusion is more likely than anyone else to … - Robert Sheckley

How does the fool build his paradise?—out of the crumbling bricks of illusion and the watery cement of hope.

Few individuals of any race murder for pleasure. There are perfectly adequate reasons to kill, though, reasons which might satisfy any philosopher.
But, once accepted, there are more reasons, and more and more. And murder, once accepted, is hard to stop. It leads irresistibly to war and, from there, to annihilation.

It was an eccentric sort of event, even for Esmeralda, and needed a special kind of person to volunteer to do it. Luckily, the human race has never thought up anything so ludicrous, dangerous, and frivolous that it won’t attract many willing volunteers.