“The history of ideas… develops to an indispensable degree on the basis of criticism. A puts forward a theory, and is then followed by B, who perceives not only its value but some of its shortcomings, and puts forward a new theory which subsumes what is good in A’s without containing its perceived faults. Then along comes C, who does exactly the same with B’s theory. And so it goes on indefinitely – albeit untidily, with interruptions, detours, zig-zags, journeys up blind alleys and garden paths, waves of reaction, and so on.”

Bryan Magee, The Philosophy of Schopenhauer, p85