"I was taught, by Popper, that if new evidence turns up, it is quite wrong to modify the hypothesis to accommodate it. The hypothesis should be scrapped and a new one formulated. Popper instanced Marx’s theory of political economics as an example of a bad hypothesis made worse by being allowed to accommodate new historical facts as they occurred. And he gave Freud’s theories as an even worse example of this fundamental weakness. Those who stick to an inanimate explanation of the universe are equally guilty of breaking Popper’s Law. All they have produced so far, and they have been at it for a century now, is constant change and fiddling, and the present state of the theory or theories is immensely complicated, almost impossible to understand, and impermanent."