 Horkheimer’s conception of interdisciplinary social research is rooted in, broadly construed, both empiricist and realist views. Horkheimer speaks often of such research as aiming at “facts,” as seen in §2.1 when he refers to the desire for happiness as a natural fact. This connects to a kind of realism seen most directly in the 1935 essay “On the Problem of Truth.” “Materialism” he tells us, “insists that objective reality is not identical with man’s thought,” and truth is determined by the “relation of the propositions to reality” (pp. 189, 194). But this realism has to be qualified; materialism is distinguished from idealism through the appeal to an objective reality outside of our thinking, but it is further separated from metaphysical realism by its recognition that our knowing is historically bounded. Along these lines, Horkheimer admits to holding to a correspondence theory of truth, but notes that: