a generation that cannot endure boredom will be a generation of little men, of men unduly divorced from the slow process of nature, of men in whom every vital impulse slowly withers as though they were cut flowers in a vase.

A smile happens in a flash, but its memory can last a lifetime.

When you are studying any matter or considering any philosophy, ask yourself only: what are the facts, and what is the truth that the facts bear out. Never let yourself be diverted by what you wish to believe, but look only and surely at what are the facts.

The degree of one's emotions varies inversely with one's knowledge of the facts - the less you know the hotter you get.

The human race may well become extinct before the end of the century. Speaking as a mathematician, I should say the odds are about three to one against survival.

What men really want is not knowledge but certainty.

Every sane and sensible and quiet thing we do is absolutely ignored by the press.