This short paper is about the generalized evolutionary approach to the economics of science. Stephen Toulmin and David Hull are pioneers of the former rather than Karl Popper whose falsification thesis was sociologically naive. Useful directions for the future would go beyond the generalities of variation, transmission and selection towards making more explicit use of Darwin’s “two great principles.” The first is “the unity of types” i.e. common descent by employing phylogenetic methods to answer historical questions. The second is “the (...) conditions of existence” i.e. natural selection by making use of general principles of evolutionary ecology and socioecology to answer questions about why something evolved. (shrink)