This dissertation defends materialism from the epistemic arguments against materialism. Materialism is the view that everything is ultimately physical. The epistemic arguments against materialism claim that there is an epistemic gap between physical and phenomenal truths (for example, that knowing the physical truths does not put you in a position to know the phenomenal truths), and conclude from this that there is a corresponding gap in the world between physical and phenomenal truths, and materialism is false. Chapter 1 introduces materialism and the arguments against materialism that I respond to in this dissertation. Chapters 2 and 3 explore the phenomenal concept strategy (PCS), one promising materialist response to the epistemic arguments against materialism. The PCS admits that there is an epistemic gap between physical and phenomenal truths, but claims that it arises because of something special about our concepts of consciousness and not because of something special about consciousness itself. Chapter 4 considers what reason there is to think that there is an epistemic gap between physical and phenomenal truths in the first place. I argue that some arguments might succeed in showing that there is such an epistemic gap, but that if these arguments succeed then they end up vindicating the PCS. Chapter 5 considers more generally what is required for an epistemic gap to exist. In particular, it considers whether conceptual analysis is necessary to close an epistemic gap.