Pragmatism was not the first to apply evolution to theories of knowledge: Schopenhauer advocated a biological idealism as what's useful to an organism to believe might differ wildly from what is true. Here knowledge and action are portrayed as two separate spheres with an absolute or transcendental truth above and beyond any sort of inquiry organisms used to cope with life. Pragmatism challenges this idealism by providing an "ecological" account of knowledge: inquiry is how organisms can get a grip on their environment. "Real" and "true" are functional labels in inquiry and cannot be understood outside of this context. It is not "realist" in a traditionally robust sense of realism (what Hilary Putnam later called metaphysical realism), but it is realist in how it acknowledges an external world which must be dealt with.