The entire point of the scientific method is to rule out premises that are contradicted by observations. It has never meant beginning with premises you know to be false and absurd, tracing out whatever implications you can draw from there, and, when circumstantially finding congruence with your “predictions” and observed data, asserting the result of your machinations as “scientific knowledge.”
The reader should now be able to note just how shaky and peculiar the methodological stance of positivist, or rather “positive,” economics actually is. In Friedman’s essay, “The Methodology of Positive Economics,” he defends deriving consequences from clearly false premises with regard to the study of human action. He aptly states that hypotheses are not required to be “realistic” in their assumptions.
Unfortunately for him, a “hypothesis” that incorporates notions and assertions that are demonstrably false is not a hypothesis but a falsehood. Many of the falsehoods that are defended by him, like homo economicus, perfect competition, and perfect knowledge, are still applied in neoclassical economics today.
One can identify from Friedman’s essay a confusion about the way in which assumptions are utilized in the natural sciences. Systems are never modeled according to assumptions that are fantastically flawed in describing them. If physics is truly the science that modern neoclassical economists seek to emulate, it is unfortunate for them that they have utterly misunderstood its methodology. Much of what is labeled “economics” today therefore cannot correctly be described as a science.
The intrinsic non-science is a very important point that I implied, but never quite managed to state so succinctly in RGD. But in significantly fewer words, this is what I was working towards getting across to the reader in the chapter “N-body economics”.