Pinker continues his analysis of language and thought in The Stuff of Thought beginning with an an analysis of non-obvious regularities in verb usage in English. The theme throughout this book is that the regularities in language reveal the human conceptual framework that underlies language and thought. He starts by examining direct- / indirect- object exchange ('he loaded the wagon with hay' vs. 'he loaded hay into the wagon'). He identifies the two concepts at work in these formulations: changing the state of the container vs. moving the contained objects. Then he moves on to show how this only works for certain types of verbs. In this way he ends up with a system of 6 core concepts that must, in his view, underlie thought. Subsequent chapters examine innate- vs. learned concepts, the information that can be gleaned from our constant use of metaphor, and the significance of names.
This is another amazing achievement by Pinker. I did not spend nearly enough time with this book to write a proper synopsis. All I can say is that if you are interested in the theory of mind, read any of Pinker's books. If you are interested in a non-Chomskian theory of language, read this book.