In this book, Jolley aims to understand the 'concept horse' debate between Frege and Kerry. But Jolley's purpose is not so much to champion either side; rather, it is to utilize an understanding of the debate to shed light on the work of Ludwig Wittgenstein-and vice versa. Jolley not only sifts through the debate between Frege and Kerry, but also through subsequent versions of the debate in J. J. Valberg and Wilfrid Sellars. Jolley's goal is to show that the central notion of Philosophical Investigations, that of a 'conceptual investigation', is a legacy of the Frege/Kerry debate and also a contribution to it.