Fantastic book on natural kinds and induction. There are two main questions that Kornblith addresses:
1) what is the world like that we can know it?
2) how are we such that we can know the world
To address the first question, Kornblith focuses on the work of Locke on induction and shows that arguments against natural kinds (varieties of conventionalism) fail. Natural kinds are homeostatic clusters, and we should rely on our sciences to identify them.
To address the second question, he focuses on empirical work on human cognition and rationality. Crossing over work by human development psychologists, Chomsky and Kahneman and Tyversky, Kornblith argues that we should not concede ground to quinean minimalists as there is ample evidence that we have innate perceptual capacity for natural kinds.
It would be interesting to see whether the empirical work of the last ~30 years supports this view or not!