At two-tenths the speed of light, dust and atoms might not do significant damage even in a voyage of 40 years, but the faster you go, the worse it is--space begins to become abrasive. When you begin to approach the speed of light, hydrogen atoms become cosmic-ray particles, and they will fry the crew. ...So 60,000 kilometers per second may be the practical speed limit for space travel.

The vast majority, who believe in astrology and think that the planets have nothing better to do than form a code that will tell them whether tomorrow is a good day to close a business deal or not, become all the more excited and enthusiastic.

Society is much more easily soothed than one's own conscience.

It's the writing that teaches you.

Self-education is a continuing source of pleasure to me, for the more I know, the fuller my life is and the better I appreciate my own existence

To bring about destruction by overcrowding, mass starvation, anarchy, the destruction of our most cherished values, there is no need to do anything. We need only do nothing except what comes naturally, and breed. And how easy it is to do nothing

Until I became a published writer, I remained completely ignorant of books on how to write and courses on the subject ... they would have spoiled my natural style; made me observe caution; would have hedged me with rules.