Abstract
This chapter accepts for the sake of argument Ronald Dworkin’s point that the only viable form of normative skepticism is internal, and develops an internal skeptical argument directed specifically at normative realism. There is a striking and puzzling coincidence between normative judgments that are true, and normative judgments that causal forces led us to believe—a practical/theoretical puzzle to which the constructivist view has a solution. Normative realists have no solution, but are driven to conclude that we are probably hopeless at recognizing the independent normative truths they posit. Since this is an unacceptable conclusion, we must conclude that normative realism is false. Drawing on evolutionary considerations, it is explained why this internal skeptical argument does not carry over to our knowledge of objects in our manifest surroundings, and why the challenge does not depend on any assumption that the epistemology of the normative domain must be a causal one.