It is an intriguing paradox of present Western culture that, while the dream of a unified system of scientific knowledge has never been more alive, there is a growing doubt that any universally valid knowledge may ever be possible. The success of Newton's astonishing insights pales when compared with the successes of the Theory of Relativity and Quantum Mechanics. On the other hand, the scepticism of Hume which in the eighteenth century had awakened Kant from his "dogmatic slumber" and impelled him to investigate the conditions of universally valid knowledge of fact, seems to be child's play when it is compared with the onslaught of the attacks upon the "received view" of the nature of science, that were perpetrated by Popper, Kuhn, social constructivism, and post-modernism which seems to be the latest bandwagon from which a wide variety of intellectual guerilla fighters feel free to shoot from the hip on their favorite target.