Abstract
This chapter argues that materialism is vulnerable to two kinds of epistemological objections: transcendental arguments, that show that materialism is incompatible with the very possibility of knowledge; and defeater arguments, that show that belief in materialism provides an effective defeaters to claims to knowledge. It constructs objections of these two kinds in three areas of epistemology: our knowledge of the laws of nature (and of scientific essences), our knowledge of the ontology of material objects, mathematical and logical knowledge. The chapter argues that these epistemological weaknesses place the materialist in a dialectically weak position in respect of ontological identity claims, since the materialist cannot know the causal powers or persistence conditions of material objects. It also argues that the materialist can provide no non-circular account of epistemic normativity. Anti-realist accounts of normativity are unavailable because normativity is already implicated in all intentionality. Moreover, materialists face a fatal dilemma in attempting to carry out an etiological reduction of teleological norms, since neither Humean nor anti-Humean accounts of causation yield defensible results.