"The deity of Leibniz and Maupertuis can only make action stationary; to us remains the challenge to make the world as good as possible.... We can neither evade such problems nor address them without science. Ekeland's admirable account gives us the tools to consider these important questions in greater depth." - Peter Pesic, Times Literary Supplement "A vivid picture of human history and destiny.... Ekeland moves easily from mathematics to physics, biology, ethics, and philosophy." - Freeman Dyson, New York Review of Books "[Ekeland's] explanations are clear and elegant... and his prose is fluid, exhilarating, and suspenseful. I tried to put this book down after chapter 4 but couldn't. It was as if some compelling force of nature had a purpose, an opposing directive in the best of all possible worlds." - Joseph Mazur, Nature"