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.

It goes with the passionate intensity and deep conviction of the truth of a religious belief, and of course of the importance of the superstitious observances that go with it, that we should want others to share it - and the only certain way to cause a religious belief to be held by everyone is to liquidate nonbelievers. The price in blood and tears that mankind generally has had to pay for the comfort and spiritual refreshment that religion has brought to a few has been too great to justify our entrusting moral accountancy to religious belief.

Psychoanalytic theory is the most stupendous intellectual confidence trick of the twentieth century and a terminal product as well-something akin to a dinosaur or zeppelin in the history of ideas, a vast structure of radically unsound design and with no posterity.

The attempt to discover and promulgate the truth is nevertheless an obligation upon all scientists, one that must be persevered in no matter what the rebuffs—for otherwise what is the point in being a scientist?

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.

There is much else in the literary idiom of nature-philosophy: nothing-buttery, for example, always part of the minor symptomatology of the bogus.

An experiment not worth doing is not worth doing well.