It is a grave difficulty in the analytical treatment of scientific ideas that the simple laws are so vaguely conceived that analysis is difficult and the theories that are precisely formulated are often put forward as dogma and the evidence in favor of them has sunk into oblivion or into the realm of myth.

Scientific Method: An Inquiry into the Character and Validity, of Natural Law, Chapter VI (p. 157), Kegan Paul, Trench, Trubner & Co., Ltd. 1923