Quinian bootstrapping is Susan Carey's solution to Fodor’s paradox of concept learning. Carey claims that contrary to Fodor’s view, not all learning amounts to hypothesis testing, and that there are ways in which even primitive concepts can be learned. Recently Georges Rey has argued that Carey’s attempt to refute radical concept nativism is unsuccessful. First it cannot explain how the expressive power of mental representational systems could increase due to learning. Second, both Fodorian circularity charges and Goodmanian problems of indeterminacy apply to Carey’s examples of Quinian bootstrapping. I argue that Carey’s examples of bootstrapping can be amended to escape Fodorian and Goodmanian objections. I suggest some ways to improve on our models of concept learning to this end. I also argue that skill learning is the way for mental representational systems to increase their own expressive power, that is, to enrich their conceptual repertoire beyond what compositionality alone affords.