With all of these limitations and hazards well in mind, let us ask whether a knower so conceived is capable of constructing the physics of the world which includes himself. But, in so doing, let us be perfectly frank to admit that causality is a superstition.
p. 148. Chapter: Through the Den of the Metaphysician; cited in: Heinz von Foerster (1995) Metaphysics of an experimental epistemologist. (online) - Embodiments of Mind, (1965)