Where Our Number Concepts Come From.

Like most cognitive scientists, I take concepts to be mental symbols. Mental symbols are not all concepts, as there are also sensory representations, motor representations, and perceptual representations. From the perspective of cognitive science, a theory of concepts must specify their format, what computations they enter into, what determines their content, and how they differ from other types of mental symbols. In a recent book (Carey, in press) I present case studies of the acquisition of several important domains of conceptual representations, arguing that the details of the acquisition process adjudicate among rival theories of concepts within cognitive science. The case studies bear on the existence and nature of innate concepts, and on the existence and nature of discontinuities in development. Human conceptual development involves the construction of representational resources that go beyond those from which they are built in theoretically interesting ways. As Fodor (1975, 1980) has forcefully argued, characterizing these discontinuities and explaining how they are possible is a formidable challenge to cognitive science. Meeting this challenge informs our theories of the human conceptual system.