critical-realism message, BHA: Epistemological relativism

Heikki Patomaki states in, After International Relations: Critical Realism and the (Re) Construction of World Politics, that "I define critical realism in terms of a well-articulated ontological realism, epistemological relativism and judgemental rationalism" (p93).

What do people make of the claim that CR adopts epistemological relativism? Given that one is an epistemic relativist how does one justify judgemental rationalism?

To assert that the natural world is "real" but that our knowledge of it is a mere social construction, that it does not exist outside of "geo-historical processes" (p144) as far as I can see is anything but a "realist philosophy of science". To speak frankly I do not see how an epistemic relativist can claim that the world is "real" if our knowledge of it is a mere social construction. Thus to say that the natural world is real, according to Patomaki, is itself a social construction. Thus it might be real but then again when society is reconstructed it may well turn to be unreal, then real again and so on. A realist "philosophy of science" must be concerned with our knowledge of the world not the world itself. Patomaki is thus no realist. And if CR adopts epistemic relativism then neither is it. One must be an epistemic realist.

Patomaki it seems to me believes in supernatural forces. He claims that "different, emergent layers (such as biological, human and social) are ontologically irreducible" (p8). Thus human nature has nothing to do with biology nor do human social systems have anything to do with human nature. If human nature cannot be reduced to biology then where does human nature come from, God? If so, as a realist, he must prove that the supernatural is real. If only the natural is real then human nature and human social systems are natural kinds not "social kinds".