This book examines the significance of Whitehead's first year of lectures at Harvard, recently published in the first volume of The Edinburgh Critical Edition of the Complete Works of Alfred North Whitehead. In these newly commissioned essays, leading Whitehead scholars ask a range of important questions: Do these lectures challenge or confirm previous understandings of Whitehead's published works? What is revealed about the development of Whitehead's thought in the crucial period after London but before the publication of Science and the Modern World? What should we make of concepts and terms that were introduced in these lectures but were never incorporated into subsequent publications? The lectures published in The Harvard Lectures of Alfred North Whitehead, 1924-1925: Philosophical Presuppositions of Science represent Whitehead's first American lectures in philosophy after a long career in England as a mathematician and throw new light on the development of his philosophy. Also included in this volume is the text of Whitehead's first lecture at Harvard, recently gifted to the Critical Edition of Whitehead, allowing for a clearer understanding of Whitehead's plans and goals for his first course of lectures in philosophy than has previously been possible. Brian G. Henning, Founding Executive Editor of the Critical Edition of Whitehead, is Professor of Philosophy and Environmental Studies at Gonzaga University in Spokane, Washington. Joseph Petek, Assistant Editor of the Critical Edition, is a doctoral candidate in process studies at Claremont School of Theology.