  The mind is not able to come up with new ideas on its own, that is, it is unable to direct creativity. Thus, variation is not directed, but science relies on fantasy, chance, luck, etc., for production of its ideas. Once produced, scientists choose those ideas which best fit the facts. Mach also comments on the debates over whether reasoning, inductive or deductive, can produce knowledge, arguing that reasoning cannot by itself produce knowledge, but rather can only operate on existing variation: “Thus syllogism and induction do not create new knowledge, but merely make sure that there is no contradiction between our various insights and show clearly how these are connected, and lead our attention to different sides of some particular insight, teaching us to recognize it in different forms. Obviously, then, the genuine source from which the enquirer gains knowledge must lie elsewhere.” [KE: 231]