An important point of agreement between Generative Realism and the postmodernists is the rejection of scientific epistemological hegemony. Scientific methodology and its language are a socially constructed system of concepts, but not necessarily the only system. Religion is another. You could describe the whole world as God. Those theories are are not invalid just because they are not science.
Art is another system of knowing reality.
I recently saw the van Gogh collection in the Amsterdam museum and it is a particular view, or statement, of reality that is as valid as any other when held against the criterion of experience. In science, something is a true fact because its methodological observation says so. In religion, something is a true fact because Scripture or revelation says so. Science does not have the market cornered on facts. Generative Realism agrees with postmodernism on that score.