Turing: Pioneer of the Information Age by B. Jack Copeland (review)

Some individuals come to symbolize scientific paradigm shifts—Einstein, Hawking, even Stephenson. Their names become a public shorthand for a revolution in thought; they are widely referenced in the popular press but often with only a shallow understanding of their technical contribution. Alan Turing seems to be in the process of achieving this symbolic status for several different constituencies at once—inventor of the computer, winner of the Second World War, martyr to gay rights. None of these claims withstands careful scrutiny, but lazy writers can construct plausible narratives on these themes—at the time of this writing, films on the life of Turing and of Hawking are competing for awards. Neither claims historical accuracy. Both are powerful examples of myth making.

B. Jack Copeland is not a lazy writer, and this book displays scholarship in depth—a 240-page narrative is supported by fifty pages of notes and a twelve-page index. The book is perhaps best understood as an attempt to build a concise biography of Alan Turing in the popular science style, but with an underpinning of academic credibility. The story proceeds at a lively pace. A nine-page introductory overture is followed by a chronological account of Turing’s short life in only 150 pages: two chapters on prewar research in Cambridge and Princeton; two chapters on Enigma and Hut 8; and two chapters on Tunny and Colossus with careful attribution of credit to Tommy Flowers. These are rounded off with chapters on the ACE computer design, and on the Manchester Baby and successor machines.

The narrative is full of interesting personal detail, and captures little-known fragments which illuminate the character of the protagonists—for instance the incident in which Donald Davies at the National Physical Laboratory challenged Turing over typographic errors in the seminal “On Computable Numbers,” to Turing’s apparent irritation. I have a copy of the paper with handwritten corrections that Donald gave me some years ago, along with verbal anecdotes that certainly corroborate Copeland’s account (Copeland cites as his source the London Science Museum’s Oral History of Computing project). This combination of popular science anecdote combined with detailed citation is characteristic of Copeland and worthy, but there are places where the treatment tilts over into the kind of color that only a novelist can reasonably supply: at the beginning of chapter 2 we are told of Max Newman striding energetically through St John’s to lecture the attentive Turing, that the light was bleak and gray, and that the ancient Colleges seemed older still as a result. It is hard to know how these things are known, and the prose is a little starry for my tastes. Nevertheless, it makes for a good read.

A significant weakness of the book, for both casual and academic readers, is the lack of a unified bibliography and guide to the broader Turing literature, coupled to a high level of self-citation. On page 52, for instance, we are told that Turing wrote an explanation of the Enigma break in an earlier Copeland book, which reads very oddly. The primary source is Turing’s “Treatise on the Enigma” which is available online from the King’s College archive.

The last third of the book shifts perspective as Copeland discusses artificial intelligence, interspersed with a fragmentary description of Turing’s ideas on consciousness and of his guilty plea to charges of gross indecency and subsequent hormone treatment. There is an extensive treatment of the Turing test, which leads into a discussion of Joseph Weizenbaum’s ELIZA and a variety of philosophical responses to the validity, or otherwise, of the test. This is home territory for Copeland, much of whose work is in philosophy and logic, but I found it sat uncomfortably with earlier parts.

The final chapter concerns Copeland’s thesis that the coroner’s verdict of suicide might not have been returned by a more probing investigation. The postmortem concluded that death was by cyanide...