“I do have witnesses to one of my journeys in a space craft. Both are scientists who hold high positions. Once they are able to make a statement the picture will change overnight. However, the way things are nowadays with everything classified as security, for the time being they must remain in the shadow. When they believe that they can release the substantiation they have without jeopardizing either the national defense or themselves, they have said that they will do so through the press. How soon that will be, your guess is as good as mine. But because they were with me at the request of the Brothers, some things are moving in behalf of both the Brothers and the general public that otherwise could not have been started. And much as we would like to, we cannot speak of these things yet because good intentions can have bad reactions. Anything acted upon prematurely can ruin the best beginnings.”

"A Half Life" (1990), pp. 302-303
It All Adds Up (1994)
Context: There's something that remains barbarous in educated people, and lately I've more and more had the feeling that we are nonwondering primitives. And why is it that we no longer marvel at these technological miracles? They've become the external facts of every life. We've all been to the university, we've had introductory courses in everything, and therefore we have persuaded ourselves that if we had the time to apply ourselves to these scientific marvels, we would understand them. But of course that's an illusion. It couldn't happen. Even among people who have had careers in science. They know no more about how it all works than we do. So we are in the position of savage men who, however, have been educated into believing that they are capable of understanding everything. Not that we actually do understand, but that we have the capacity.

"The Comedies of William Congreve" in William and Mary College Monthly (September 1897), V, p. 41, as quoted in "James Branch Cabell at William and Mary: the Education of a Novelist," by William L. Godshalk in The William and Mary Review, 5 (1967); reprinted in Kalki, Vol II, No.4, Whole No.8 (1968) http://www.silverstallion.karkeeweb.com/kalki_archives/kalki_from.html

Source: The Science of Rights 1796, P. 7-8

Nobel lecture (1973)

Books, Islam and the West: A Conversation with Bernard Lewis (2006)

Note in the appendix of Grundlagen der Arithmetik (Vol. 2) after Frege had received a letter of Bertrand Russell in which Russell had explained his discovery of, what is now known as, Russell's paradox.
Grundgesetze der Arithmetik, 1893 and 1903

Source: Dirk Gently's Holistic Detective Agency

Speech http://hansard.millbanksystems.com/commons/1842/mar/11/financial-statement-ways-and-means in the House of Commons (11 March 1842).

Quasar, Quasar, Burning Bright (1978), p. 235
General sources