The endeavor of scientific research to see events in their more general connection in order to determine their laws, is a legitimate and useful occupation. Any protest against such efforts, in the name of freefom from restrictive conditions, would be fruitless if science did not naïvely identify the abstractions called rules and laws with the actually efficacious forces, and confuse the probability that B will follow A with the actual effort make B follow A.
p. 150. - "The Latest Attack on Metaphysics" (1937)