“It is just in thinking all these elements in an active originating Unit-thought, or an "I," that the essential and characteristic nature of man or any other real intelligence consists. Such an originating Unit-thinking, providing its own element-complex of primal thoughts that condition its experience, and that thus provide for that experience the form of a cosmic Evolutional Series, is precisely what an intelligent being is. Thus creatively to think and be a World is what it means to be a man. To think and enact such a world merely in the unity framed for it by natural causation, is what it means to be a "natural" man; to think and enact it in its higher unity, its unity as framed by the supernatural causation of the Pure Ideals, supremely by the Moral Ideal, is what it means to be a "spiritual" man, a moral and religious man; or, in the philosophical and true sense of the words, a supernatural being — a being transcending and yet including Nature, not excluding or annulling it.”

[The design revolution: answering the toughest questions about intelligent design, Downers Grove, Ill., InterVarsity Press, 2003, [BS652.D46, 2004], 2003020589, 9780830832163, http://books.google.com/books?id=sKVqpXqE0VwC] p. 8-9
2000s

Source: No Way Out (2002), Ch. 6: Seeking Strengthens Separation

Variant translation: One of the strongest motives that lead men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own ever-shifting desires. A finely tempered nature longs to escape from the personal life into the world of objective perception and thought. With this negative motive goes a positive one. Man seeks to form for himself, in whatever manner is suitable for him, a simplified and lucid image of the world, and so to overcome the world of experience by striving to replace it to some extent by this image. This is what the painter does, and the poet, the speculative philosopher, the natural scientist, each in his own way. Into this image and its formation, he places the center of gravity of his emotional life, in order to attain the peace and serenity that he cannot find within the narrow confines of swirling personal experience.
As quoted in The Professor, the Institute, and DNA (1976) by Rene Dubos; also in The Great Influenza (2004) by John M. Barry
1910s, Principles of Research (1918)
Context: Man tries to make for himself in the fashion that suits him best a simplified and intelligible picture of the world; he then tries to some extent to substitute this cosmos of his for the world of experience, and thus to overcome it. This is what the painter, the poet, the speculative philosopher, and the natural scientist do, each in his own fashion. Each makes this cosmos and its construction the pivot of his emotional life, in order to find in this way the peace and security which he cannot find in the narrow whirlpool of personal experience.

1920s, Process and Reality: An Essay in Cosmology (1929)

Alles Gescheite ist schon gedacht worden.
Man muss nur versuchen, es noch einmal zu denken.
Bk. II, Observations in the Mindset of the Wanderer: Art, Ethics, Nature
Wilhelm Meister's Wanderjahre (Journeyman Years) (1821–1829)
Variant: All truly wise thoughts have been thoughts already thousands of times; but to make them truly ours, we must think them over again honestly, till they take root in our personal experience.

Source: I Will Fear No Evil (1970), Chapter 2, p. 35

English Prose Style (1928)
Literary Quotes

Zero can never be a unit.
Definition 3. Part 1. The Elementary Conjunctions of Extensive Magnitudes. Ch. 1. Addition, Subtraction, Multiples and Fractions of Extensive Magnitudes. 1. Concepts and laws of calculation. Extension Theory Hermann Grassman, History of Mathematics (2000) Vol. 19 Tr. Lloyd C. Kannenberg, American Mathematical Society, London Mathematical Society
Ausdehnungslehre (1844)