To Think Is to Say No presents, for the first time in English, a remarkable early lecture course delivered by Jacques Derrida at the Sorbonne during the 1960–1961 academic year. Composed of four sessions and drawn from Derrida’s handwritten manuscripts, this volume offers a rare glimpse into the development of one of the most influential philosophers of the twentieth century.

Taking its title from a phrase by the French philosopher Alain—"to think is to say no"—the course explores the relationship between thinking, negation, and belief. Beginning with Alain’s provocative claim that genuine thought arises through questioning and refusal, Derrida develops what might be called a brief history of negation in Western philosophy, engaging figures from Plato, Kant, and Hegel to Husserl, Bergson, Sartre, and Heidegger. At stake is not only the logic of affirmation and negation but also the origin of thought itself: does thinking begin with a "yes" or a "no"?

Derrida’s response challenges Alain’s formulation while developing a central thread of his later philosophy: the idea of an originary affirmation of the other, a "yes" that precedes every affirmation and negation. In tracing this tension, the course reveals the early emergence of themes that would come to define Derrida’s work—language, responsibility, pedagogy, and the ethical relation to others—while showcasing his distinctive teaching style and intellectual rigor.

Edited by Brieuc Gérard and translated by Pascale-Anne Brault and Michael Naas, To Think Is to Say No brings into print a foundational document of Derrida’s thought. Both an essential contribution to Derrida scholarship and a compelling introduction to his philosophical concerns, this volume illuminates the origins of deconstruction and the enduring question of what it means to think.