The fact that scientists do not consciously practice a formal methodology is very poor evidence that no such methodology exists. It could be said-has been said-that there is a distinctive methodology of science which scientists practice unwittingly, like the chap in Moliere who found that all his life, unknowingly, he had been speaking prose.

Science is the art of the solvable.

I reckon that for all the use it has been to science about four-fifths of my time has been wasted, and I believe this to be the common lot of people who are not merely playing follow-my-leader in research.

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.

It is the great glory as well as the great threat of science that everything which is in principle possible can be done if the intention to do it is sufficiently resolute.

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

Scientists who think science consists of unprejudiced data-gathering without speculation are merely cows grazing on the pasture of knowledge.