Mathematicians and their Gods: Interactions between mathematics and religious belief
Snezana Lawrence and Mark McCartney
OUP £24.99
(978-0-19-870305-1)
Church Times Bookshop £22.50 (Use code CT470)

ONE of the triumphs of Greek mathematics is Pythagoras’ theorem, proving for all right-angled triangles a fact known to the Babylonians about some specific triangles: the square of the longest side equals the sum of the square of the other two sides.

This theorem also reveals the existence of irrational numbers: the diagonal of a square whose sides measure one unit has a length that is the square root of two. To write such an irrational number down in figures is impossible: it would take an infinite number of decimal places.

Such combinations of beautiful eternal truths and infinite possibilities have often struck mathematicians, among them atheists, as somehow significant. Some mathematicians, however, have gone further and have seen mathematics and the divine as linked. This book, as its subtitle indicates, explores these interactions between mathematics and belief.

The book’s focus is on the Western world and thus largely on Christianity in relationship to mathematics (although chapters also consider Ancient Greek religion and Freemasonry). Together with an introduction, 12 short case studies discuss examples from 2000 and more years of mathematical thought, from Pythagoras to the 20th-century logician Kurt Gödel.

While this creates considerable variety, it also causes the greatest weakness of the book. Each chapter must provide not only an introduction to the mathematician(s) discussed, but also to their sometimes unorthodox theology and its connections to their work, which itself may be hard to explain. All this is difficult to do in such a short compass. In the most successful chapters, such as those on Renaissance combinatorics, Johannes Kepler, Isaac Newton, and Maria Gaetana Agnesi (the first known woman to publish a book on mathematics), the reader does get a sense of how a particular vision of God coheres with mathematical insights. Some other chapters, however, end up as little more than potted histories of a mathematical field.

The amount of mathematical detail provided also varies greatly: some chapters include equations and diagrams, and others none. In general, the authors presume a relatively high level of scientific and mathematical knowledge among their readers. I found some chapters difficult to follow; less mathematically minded readers might struggle more. In addition, although the number of illustrations in the book is welcome, some are hard to see clearly, such as the details of the cover of Flatland, the mathematical “romance of many dimensions”.

Overall, the book falls somewhat between stools: insufficiently detailed for serious historians of science, but without enough explanation of either the historical or mathematical background for readers who are not familiar with one of these aspects. Nevertheless, it raises intriguing possibilities, and suggests that more detailed studies of specific mathematicians would provide food for historical and theological thought.

Dr Rachel Stone is Visiting Research Associate in the Department of History, King’s College, London.