Biologically the species is the accumulation of the experiments of all its successful individuals since the beginning.

The professional military mind is by necessity an inferior and unimaginative mind; no man of high intellectual quality would willingly imprison his gifts in such a calling.

Science is a match that man has just got alight. He thought he was in a room - in moments of devotion, a temple - and that his light would be reflected from and display walls inscribed with wonderful secrets and pillars carved with philosophical systems wrought into harmony. It is a curious sensation, now that the preliminary splutter is over and the flame burns up clear, to see his hands and just a glimpse of himself and the patch he stands on visible, and around him, in place of all that human comfort and beauty he anticipated - darkness still.

It sounds plausible enough tonight, but wait until tomorrow. Wait for the common sense of the morning.

I want to go ahead of Father Time with a scythe of my own.

The too perfect security of the Upper-worlders had led them to a slow movement of degeneration, a general dwindling in size, strength, and intelligence.

After people have repeated a phrase a great number of times, they begin to realize it has meaning and may even be true.