 The research program of logical positivism of the Wiener Kreis in the first half of the twentieth century revitalized the older project of empiricism. Its ambition was to reconstruct scientific knowledge on the basis of direct observations and logical relation between statements about those observations. The old criticism of Kant on empiricism was revitalized by Quine (1951). Within the framework of logical positivism induction was invalid and causation could never be established objectively. In his Logik der Forschung (1934) Popper formulates his well-known demarcation criterion and he positions this explicitly as a solution to Hume’s problem of induction (Popper 1934 [1977: 42]). Scientific theories formulated as general laws can never be verified definitively, but they can be falsified by only one observation. This implies that a theory is “more” scientific if it is richer and provides more opportunity to be falsified: