Qualitative change is widely recognized as a defining feature of evolution. Schumpeter and Georgescu-Roegen put it at the center of their methodological reasoning. I revisit important contributions of these two authors, paying attention to the immediate relationship of the major traits and treated issues between their works. With reference to qualitative change, their joint approach provides answers as to (i) why an evolutionary analysis has to necessarily apply a varied less formal set of methods as compared to modern static and dynamic analysis, (ii) why an evolutionary analysis is a necessary component of economic analysis, and (iii) how it can be seen as complementary to modern statics and dynamics. They argued for methodogical pluralism, where the choice of methods shall derive from close observation of the subject matter under scrutiny. Georgescu-Roegen's reasoning shows the necessity of interdisciplinary contributions and the interrelation of economic activity and environmental impact and constraints, putting environmental issues immediately on the evolutionary economics agenda. The paper provides a new ground for evaluating Georgescu-Roegen's own and their joint contribution to modern research.