"Logically, that gives us no clue as to how the "objective" world might be; it merely means that we know one viable way to a goal that we have chosen under specific circumstances in our experiential world. It tells us nothing -- and cannot tell us anything -- about how many other ways there might be, or how that experience which we consider the goal might be connected to a world beyond our experience. The only aspect of that "real" world that actually enters into the realm of experience, are its constraints; or, as Warren McCulloch, one of the first cyberneticists, so dramatically said: "To have proved a hypothesis false is, indeed, the peak of knowledge""-Ernst von Glaserfeld
A philosopher of science known as Karl popper argues that the true process of science is to challenge the existing theories about the world and establish new ones which will in turn be discredited. In otherwords, all science is, is a process of discrediting other ideas and finding new ones that explain the world in a better way, until they themselves fail to work, or there is a flaw. Glaserfeld, in his article actually discusses popper, and claims that Popper's arguments actually support radical constructivism because we can only see what ideas line up with our own personal reality, and what ones do not. Science is then the study of what lines up with our experience of reality and what does not.
However, Popper argues that we base our observations on external reality. He claims that even if we can never get a true theory without massive amounts of work, these theories are making statements about the external world, while Glaserfeld argues that they come from internal experiences. Glaserfeld is then misapplying Poppers theories about science in a way that suits his own purposes and is yet another flaw in Glaserfeld's argument.
