To look at a portrait of Descartes, one would consider him somewhat of a fop. And if one were to strictly consider Descartes' contributions to mathematics and philosophy, then he might be seen as a nerdish fop. But this portrait couldn't be farther from the reality that was Descartes' life. He was a world traveler and adventurer in addition to being one of the most brilliant minds the world has produced - before or since.

But you wouldn't know it from reading current biographies of Descartes. They are in the main turgidly written tomes; the only excitement they instill in the reader is wondering when they will end. I began to despair of there ever coming into print a biography of Descartes that captures both the thought and details of his fascinating life. Until now.

Amir Aczel combines the life and thought of Descartes in a slim breezy volume with an enthusiasm for his subject rarely seen in this sort of biography. His talent for explaining mathematical ideas and formulas that might seem daunting to the lay reader only adds to our enjoyment and deepens our appreciation for this most prolific philosopher-scientist.

To say Descartes led an interesting life is an understatement, and perhaps the most interesting thing about was the aura of intrigue and mystery in which it was enveloped. Aczel uses this as his starting point, investigating the mystery of Descartes' secret notebook which survived his death and part of which was copied by Leibniz, who easily broke the code in which it was written.

What was in this notebook that was so dangerous that Descartes felt compelled to write it in code? Aczel rightly decides to view the work in context of Descartes' life and thought, examining the charges heard in Descartes' day that he was a Rosicrucian, that he was writing heresy, and embracing the banned theories of Copernicus. Descartes, for his part, feared the Inquisition, especially after learning the fate of Galileo. He sought refuge in Holland, only to become once again embroiled in controversy. He reluctantly accepted an invitation from Queen Christina of Sweden as her personal tutor, thinking perhaps he could leave his detractors behind. But even his death in Sweden a short time later would become controversial. Did he die of natural causes, or did his enemies in the Queen's court, fearing his influence on the Queen, poison him?

And why was Leibniz so interested in copying the notebook? And why were his notes only fully understood in the late Twentieth century? Aczel tackles these issues and offers reasoned explanations based on the facts at hand. All this makes the reader want to know more about the life and thought of Descartes and his times, and that makes Aczel's book a success.