Abstract
In this chapter, I outline and defend a version of concept empiricism. The theory has four central tenets: Concepts represent categories by reliable causal relations to category instances; conceptual representations of category vary from occasion to occasion; these representations are perceptually based; and these representations are all learned, not innate. The last two tenets on this list have been central to empiricism historically, and the first two have been developed in more recent years. I look at each in turn, and then I discuss the most obvious objection to empiricism. According to that objection, some concepts cannot be perceptually based because they represent things that are abstract, and hence unperceivable. I discuss two standard examples: democracy and moral badness. I argue that both can be explained using resources available to the empiricist