*The Story of Proof* investigates the evolution of the concept of proof—one of the most significant and defining features of mathematical thought—through critical episodes in its history. From the Pythagorean theorem to modern times, and across all major mathematical disciplines, John Stillwell demonstrates that proof is a mathematically vital concept, inspiring innovation and playing a critical role in generating knowledge.

Stillwell begins with Euclid and his influence on the development of geometry and its methods of proof, followed by algebra, which began as a self-contained discipline but later came to rival geometry in its mathematical impact. In particular, the infinite processes of calculus were at first viewed as “infinitesimal algebra,” and calculus became an arena for algebraic, computational proofs rather than axiomatic proofs in the style of Euclid. Stillwell proceeds to the areas of number theory, non-Euclidean geometry, topology, and logic, and peers into the deep chasm between natural number arithmetic and the real numbers. In its depths, Cantor, Gödel, Turing, and others found that the concept of proof is ultimately part of arithmetic. This startling fact imposes fundamental limits on what theorems can be proved and what problems can be solved.

Shedding light on the workings of mathematics at its most fundamental levels, *The Story of Proof* offers a compelling new perspective on the field’s power and progress.

**John Stillwell** is emeritus professor of mathematics at the University of San Francisco. His many books include *Elements of Mathematics* and *Reverse Mathematics* (both Princeton).

"This book could well serve as a history of mathematics. … [Stillwell] has done an amazing job of collecting and categorizing many of the most important ideas in this area."—Jim Stein, *New Books in Mathematics*

"Stillwell’s *[The Story of Proof]* joins his two other Princeton University Press books in having my highest recommendation. I just wish they had been around when I was a student."—George Hacken, *Computing Reviews*

"I hugely enjoyed this book."—Jonathan Shock, *Mathemafrica*

"This book would be perfect for any keen undergraduate, keen amateur, or indeed a teacher of mathematics, who wants a book to dip into to use for the classroom."—Jonathan Shock, *Mathemafrica*

"A well-crafted, thought-provoking meditation on the concept of proof in mathematics. . . .It is a substantive book that deserves to be read and reflected upon."—Tommy Murphy, *Irish Mathematical Society Bulletin*

"This is a work that mathematicians, historians, and philosophers will find especially engaging, as will anyone with a serious interest in mathematics and the limits of certainty that it is constantly probing."—J.W. Dauben, *Choice*

"Stillwell's book is fundamentally an ode to mathematical progress and a retrospective on how far we have come in developing a mathematically sound theory of proof itself."—Alexi Block Gorman, *The Mathematical Intelligencer*

“I am a great admirer of Stillwell’s writing, and this book does not disappoint. Ranging broadly and authoritatively over the history of mathematics, he takes the reader into those places where proofs have been innovative and have played a critical role.”—David M. Bressoud, author of *Calculus Reordered: A History of the Big Ideas*

"This is a lively story of the way that mathematics develops new concepts and ideas in order to solve hard problems. It is, at the same time, a story of the way that logic and the theory of computability emerged organically from reflection on mathematical method and thought. This book will be highly valuable to anyone interested in contemporary mathematics and how it came to be."—Jeremy Avigad, Carnegie Mellon University

“*The Story of Proof*—a book about mathematics as proof, and proof as mathematics, through the ages—is unique and enjoyable."—Anil Nerode, Cornell University