Naturalism supposes unification of evolution throughout the humanities and the sciences; in this special respect it urges co-evolution of nature, culture, society and the economy. Currently there are two major attempts which tackle such a naturalistic foundation in evolutionary economics. First, there is a Darwinian perspective on naturalism, as generalized Darwinism (GD) proposes, and second, there is a generic (GN) perspective on naturalism, as advocated within the continuity hypothesis and evolutionary realism. Whereas the former (GD) works with the Darwinian vocabulary, the latter (GN) tries to identify a new vocabulary beyond the special case of biological evolution. The next sections give an introduction into these ontological claims and their related discussions.