The Parrot's Theory is part fable, part magical realism, and part treatise on the history and major threads of mathematics. The obvious comparison to be drawn is with Sophie's World, and certainly it is difficult to think that this book was not inspired by Jostein Gaardner's bestseller.
Around a mystical quest centering on a parrot found in the Clingnancourt flea market, a truckload of books by a reclusive mathematician and the unruly home life of a single parent and her bookish friend, Guedj teases out a history of Mathematics, from the ancient Greeks to the solution to Fermat's Theorem.
Max, the youngest son in the disfunctional family is the one who finds the parrot being mistreated in the flea market and brings it home. His mother, an intelligent, able woman, and Max's brother and sister are twins. Their friend Monsieur Ruche runs the neighbouring bookshop and is close to mother and children.
The parrot is uncommon because it does no talk, it speaks - in cogent, intelligent responses it discusses mathematics with anyone who will listen. M. Ruche, an elderly ex-mathematician teases out the birds non-sequiters into stories of the greek Mathematicians. The children (somewhat implausibly in present day France) are enchanted.
Then M. Ruche receives a letter from his old friend the reclusive mathematician M Grosrouvre (pun on Magnum Opus), advising him that he is sending his library of maths books from his jungle hideout to M Ruche. The books duly arrive -several truck loads - and the children help M. Ruche to catalogue them in his bookshop.
The Parrot's Theory is never laboured. The characters are genuinely charming, their dialogue fresh, modern and lacking the stilted politeness of much adolescent fiction. If one suspends disbelief to accept their fascination with maths, then one enjoys their company. Equally, Geudj is a confident and inventive instructor in maths, the book is an exemplary treatment of a very difficult subject. One might argue that it is not entirely appropriate to treat it in this way, but I feel Guedj has paid due attention to story, character and maths. It has, at times, real pace of narrative, and the fact that Grosrouvre was working on theories related to Wiley's proof seems to draw the story inevitably from the mathematics of Thales to the present day. It is easy to understand why people might buy this book: whether familiar with the maths, or barely aware of them, the book seems to make them tangible.