The Man Who Knew Too Much: Alan Turing and the Invention of the Computer

All students studying computer science are introduced to Alan Turing at one time or another. For most, this introduction takes the form of Turing as the inventor of the Turing Machine, a machine unbounded by time and memory that can solve any problem. Once the students perform some perfunctory exercises involving the use of a Turing machine to construct say, the solution to the dining philosophers problem, they promptly forget about Turing and his machine. Which is so sad. Turing can be rightly considered the father of the modern computer where data and memory are mapped to the same address space. This invention is typically attributed to John von Neumann, but the author of the book makes a point that behind von Neumann's contribution was Turing's hand. Turing went on, in his brief life spanning only 42 years, to work on cryptography (credited with decoding the German Enigma machines in World War II, albeit using the groundwork laid down by a Polish cryptographer, Martin Rejewski; see Simon Singh's Code Book reviewed in 2006), artificial intelligence (the Turing Test), and mathematics. The state saw to it that his genius would be, unfortunately, eclipsed by his sexuality. In 1952, Turing was convicted of "acts of gross indecency" after admitting sexual relations with a man. He was forced to undergo hormone therapy in the vain hope of "curing" him. Instead, what these pogroms did was to rob the scientific world of one of the greatest researchers of all times. Turing elected to end his life by biting into an apple laced with cyanide. It was apropos; his favorite fairy tale was Snow White and the Seven Dwarfs.

To describe someone as "ahead of his time" is an over-used cliché. However, in Turing's case, it is appropriate in two ways. Firstly, his ideas took years to work out, and his contemporise did not realise the significance of his research. Secondly and perhaps more importantly, if he had lived in a later era, his complicated personal life would not have attracted the attention of the police, and brought about the early curtailing of the dream. David Leavitt has written an overdue appraisal of Turing that gives him credit for his successes, rather than ascribe the kudos to others because it was safer to do so. This continues the re-acclimatisation of this pioneer into a place of prominence in two fields - the research background surrounding origins of computing, and the code breaking activities that took place in Bletchley Park during World War II. It would be untrue to intimate that Turing and his colleagues at Bletchley Park "won the war", but their efforts were nevertheless of huge significance. Leavitt gives a broad overview of the activities, and points the reader to further sources. The account is perhaps romanticised, with the place of pure luck glossed over somewhat, but the scale of the code-breaking operation is realised. The description of the `Turing machine' is well presented, although not for the faint-hearted as it is necessarily very abstract thinking (again, Turing was ahead of his time). Leavitt successfully weaves Turing into a position both as a man ahead of his time, and as a man of his time (influenced by the Hilbert program in mathematics, and Kurt Gödel's revolution in logical consistency or otherwise). The seeds of what are underlying concepts of the digital age (programmable machines, stored values held digitally, and indeed binary numeric representation) are well presented. The result is to raise the stature of Turing, no longer overshadowed by the likes of John Newman. With the hindsight of more than 50 years, it is hard to imagine the treatment of Turing by not just those around him, but by `society'. Attitudes to homosexuality have changed beyond recognition, and "things would be different now". Where Leavitt is weak is not leading the reader in regard to Turing's death. However, whether suicide or an accident, Turing's death locked his ideas into a time-box from which they took time to be unpacked. Leavitt helps readers to see that they are TURING's ideas. [...]

Easy to understand book on a very complex topic. Must read at school.

As a dual computer science and English major, I find it refreshing when I stumble upon a computer science book that surveys the field from a more literary and philosophical perspective. (Galloway's "Protocol" is another example of such a work that I've encountered recently.) While Leavitt's analogies are thin at times (and the reason I give the book only 4 stars), the fact remains that if you are concerned about Turing the scientist, Turing the mathematician, or Turing the codebreaker, you have many books to choose from; this book deals with Turing in a uniquely different perspective. While Turing's homosexuality is central to Leavitt's work, he still discusses Turing's various scientific achievements, although not with a level of detail that many reviewers seem to be expecting. To those reviewers, I would say that a biography of Thomas Edison does not necessarily require a detailed account of the physical properties of the various filaments that he attempted to use in the light bulb. To do so would make the book less accessible to outside readers and would miss the point. What I find fascinating is how Leavitt manages to organize this book in a novel-like fashion such that the pace gradually quickens as we near Turing's (apparent) suicide. This is a work about the genius and tragedy that was Turing the man (and not merely "Turing the homosexual" as another reviewer so depressingly categorizes). To reduce him to just a summary of his accomplishments, as many other references on him do, is undoubtedly an injustice. To criticize this book for favoring an analysis of Turing the man over an analysis of Turing the mathematician's accomplishments is to not have read the synopsis printed on the dust jacket.

Leavitt freely admits that there is abundant documentation on the life and work of Alan Turing. I've read several of these works, and I can tell you this one is nothing like the rest. Leavitt has mastered the art of transforming Alan's complicated work into a form that truly captivates you. I had expected more on Turing's personal life, but Leavitt really concentrates his energy on revealing the inner workings of Turing through his professional and academic work. He offers perspectives that many others have totally missed. Some might challenge some of Leavitt's "reading between the lines," but most will enjoy the fresh view.