Alone among animals, humans can ponder the causes and cures of pancreatic cancer or global warming. How are we to account for the human capacity to create concepts such as electron, cancer, infinity, galaxy, and democracy.
A theory of conceptual development must have three components. First, it must characterize the innate representational repertoire—that is, the representations that subsequent learning processes utilize. Second, it must describe how the initial stock of representations differs from the adult conceptual system. Third, it must characterize the learning mechanisms that achieve the transformation of the initial into the final state. I defend three theses. With respect to the initial state, contrary to historically important thinkers such as the British empiricists, Quine, and Piaget, as well as many contemporary scientists, the innate stock of primitives is not limited to sensory, perceptual or sensory-motor representations; rather, there are also innate conceptual representations. With respect to developmental change, contrary to “continuity theorists” such as Fodor, Pinker, Macnamara and others, conceptual development involves qualitative change, resulting in systems of representation that are more powerful than and sometimes incommensurable with those from which they are built. With respect to a learning mechanism that achieves conceptual discontinuity, I offer Quinian bootstrapping.
I take on two of Fodor’s challenges to cognitive science: 1) I show how (and in what ways) learning can lead to increases in expressive power and 2) I challenge Fodor’s claim that all learning is hypothesis testing, and that the only way new concepts can be constructed is by assembling them from developmental primitives, using the combinatorial machinery of the syntax of the language of thought.