“Western civilization, it seems to me, stands by two great heritages. One is the scientific spirit of adventure — the adventure into the unknown, an unknown which must be recognized as being unknown in order to be explored; the demand that the unanswerable mysteries of the universe remain unanswered; the attitude that all is uncertain; to summarize it — the humility of the intellect. The other great heritage is Christian ethics — the basis of action on love, the brotherhood of all men, the value of the individual — the humility of the spirit.
These two heritages are logically, thoroughly consistent. But logic is not all; one needs one's heart to follow an idea. If people are going back to religion, what are they going back to? Is the modern church a place to give comfort to a man who doubts God — more, one who disbelieves in God? Is the modern church a place to give comfort and encouragement to the value of such doubts? So far, have we not drawn strength and comfort to maintain the one or the other of these consistent heritages in a way which attacks the values of the other? Is this unavoidable? How can we draw inspiration to support these two pillars of western civilization so that they may stand together in full vigor, mutually unafraid? Is this not the central problem of our time?”

poem before 1973; in a exh. cat., ed. Suzanne Delehanty (1973; repr., Philadelphia: The Falcon Press, 1976), p. 40
1970's

Source: Morals and Dogma of the Ancient and Accepted Scottish Rite of Freemasonry (1871), Ch. I : Apprentice, The Twelve-Inch Rule and Common Gavel, p. 1
Context: Though Masonry neither usurps the place of, nor apes religion, prayer is an essential part of our ceremonies. It is the aspiration of the soul toward the Absolute and Infinite Intelligence, which is the One Supreme Deity, most feebly and misunderstandingly characterized as an "architect." Certain faculties of man are directed toward the Unknown — thought, meditation, prayer. The unknown is an ocean, of which conscience is the compass. Thought, meditation, prayer, are the great mysterious pointings of the needle. It is a spiritual magnetism that thus connects the human soul with the Deity. These majestic irradiations of the soul pierce through the shadow toward the light.
It is but a shallow scoff to say that prayer is absurd, because it is not possible for us, by means of it, to persuade God to change His plans. He produces foreknown and foreintended effects, by the instrumentality of the forces of nature, all of which are His forces. Our own are part of these. Our free agency and our will are forces. We do not absurdly cease to make efforts to attain wealth or happiness, prolong life, and continue health, because we cannot by any effort change what is predestined. If the effort also is predestined, it is not the less our effort, made of our free will.

Science - The Endless Frontier (1945)
Context: Scientific progress on a broad front results from the free play of free intellects, working on subjects of their own choice, in the manner dictated by their curiosity for exploration of the unknown. Freedom of inquiry must be preserved under any plan for Government support of science...

Lecture at the Harvard Divinity School (13 March 1884); published in the The Unitarian Review and Religious Magazine as The Dilemma of Determinism http://books.google.com/books?id=38DVAAAAMAAJ&q=%22All+our+scientific+and+philosophic+ideals+are+altars+to+unknown+gods%22&pg=PA196#v=onepage (September 1884)
1880s

Source: Das Ressentiment im Aufbau der Moralen (1912), L. Coser, trans. (1961), p. 97

Herzog on Herzog (2002)

Source: after 1970, posthumous, Abstract Expressionism, Creators and Critics', 1990, pp. 167-168

Source: The Bridge on the Drina (1945), Ch. 21