“The most incomprehensible thing about the world is that it is at all comprehensible.”

Amusing Ourselves to Death: Public Discourse in the Age of Show Business (1985)
Context: The world in which we live is very nearly incomprehensible to most of us. There is almost no fact... that will surprise us for very long, since we have no comprehensive and consistent picture of the world which would make the fact appear as an unacceptable contradiction.... in a world without spiritual or intellectual order, nothing is unbelievable; nothing is predictable, and therefore, nothing comes as a particular surprise.... The medieval world was... not without a sense of order. Ordinary men and women... had no doubt that there was such a design, and their priests were well able, by deduction from a handful of principles, to make it, if not rational, at least coherent.... The situation we are presently in is much different.... sadder and more confusing and certainly more mysterious.... There is no consistent, integrated conception of the world which serves as the foundation on which our edifice of belief rests. And therefore... we are more naive than those of the Middle Ages, and more frightened, for we can be made to believe almost anything.

I'm not Stiller (1955)

“The Sanatorium at the Sign of the Hourglass” http://www.schulzian.net/translation/sanatorium/sanatorium1.htm
His father, Living things

Source: A Thousand Plateaus: Capitalism and Schizophrenia

An Apprenticeship, or The Book of Delights (1968)

Source: Gabriela, Clavo y Canela

Source: 1980s and later, Normal Accidents, 1984, p. 23

Book II, Ch. 12
Essais (1595), Book II

Source: The Dragons of Eden (1977), Chapter 9, “Knowledge is Our Destiny: Terrestrial and Extraterrestrial Intelligence” (pp. 242-243)