The Duty of Genius

I second this! In a similar, but different, vein, I also recommend Alan Turing: The Enigma, by Andrew Hodges. Do not be turned off by the useless film adaptation. The book is intelligent and fascinating, and more aimed at someone with an undergraduate level understanding of math and logic, rather than a general layperson.

My favourite nonfiction read of the year was a biography of Wittgenstein by Ray Monk called The Duty of Genius. Absolutely enthralling read about a really fascinating person. I find Wittgenstein's own writings almost impenetrable, but I feel I got to know and love the man, and his way of thinking, in this work. For fiction, I read almost all Chaim Potok's novels this year and he has become my favourite author. If anybody has a deep interest in religion, and how it interacts with the secular world, and how one is to reconcile the two, I heartily recommend Potok.