However, by combining methodological individualism and the theory of subjective evaluations and by developing a unified price theory on that basis, Menger not only shows the special fruitfulness of that combination for economic analysis.
He also shows that methodological individualism and the theory of subjective evaluations are incompatible with any essentialist approach in economics.
Menger 's investigations in the Grundsatze as well as in the Untersuchungen constitute a devastating critique of different essentialist positions, which according to Menger seriously impeded the progress of economics.