This book is about ideas and the relationship of ideas. It is not about a man. Yet it is inspired by the scholarship of Klaus Hartmann and his influence on a group of philosophers who, because of him, came to understand better the significance of Hegel's corpus and the work of other Continental philosophers, especially Kant, Husserl, Marx, and Sartre. This book is dedicated to him in gratitude. Hartmann taught about much he never directly addressed. To the editors of this volume, as students, he conveyed a sense of intellectual probity. He provided an induction into the intellectual life.