[A certain class of explanations in science are] analgesics that dull the ache of incomprehension without removing the cause.

The alternative to thinking in evolutionary terms is not to think at all.

If politics is the art of the possible, research is surely the art of the soluble. Both are immensely practical-minded affairs.

Today the world changes so quickly that in growing up we take leave not just of youth but of the world we were young in.

The bells which toll for mankind are - most of them, anyway - like the bells of Alpine cattle; they are attached to our own necks, and it must be our fault if they do not make a cheerful and harmonious sound.

Simultaneous discovery is utterly commonplace, and it was only the rarity of scientists, not the inherent improbability of the phenomenon, that made it remarkable in the past. Scientists on the same road may be expected to arrive at the same destination, often not far apart.

For a scientist must indeed be freely imaginative and yet skeptical, creative and yet a critic. There is a sense in which he must be free, but another in which his thought must be very preceisely regimented; there is poetry in science, but also a lot of bookkeeping.