464 | 42 TURING’S lEGACy
In his personal life Turing was a victim of his times. To be an active homosexual in those dark
days was to be a criminal. A mere 15 years after Turing’s arrest and prosecution the anti-gay
laws were struck down—in his small corner of the world at any rate—but in mid-twentieth-
century England an isolated maverick innocent like Turing trod dangerously. He had no pro-
tective network of powerful or worldly gay friends, and at that time he possessed no public
reputation as a war hero and leading scientist: the secrecy surrounding his wartime work meant
there could be no acknowledgement of the nation’s debt to him. Even within the scientific com-
munity the importance of his work was not obvious at the time. To most scientists in that
largely pre-computational era, his groundbreaking 1936 paper would have seemed abstruse
and irrelevant beyond the narrow field of mathematical logic. His work on artificial intelligence
and morphogenesis also had little impact during his life.
At the time of his death, Turing was a convicted criminal and an obscure Fellow of the Royal
Society. Little else was known or widely remembered. Real recognition of Turing’s scientific
contributions came long after he died, with the development of computer science and a growing
awareness of his applied work during the war.
Scientific legacy
By the 1970s and 1980s a number of popular and semi-popular science books were spreading
the word about Turing and his achievements. Herman Goldstine’s 1972 book The Computer:
From Pascal to von Neumann contained some glimpses of Turing from the point of view of an
American computer pioneer. A little later Turing appeared, if briefly, in Brian Johnson’s ground-
breaking 1977 book The Secret War, and then at greater length in Pamela McCorduck’s 1979
classic Machines Who Think. McCorduck’s excellent cameo biography of Turing, just a dozen
pages long, was the wider world’s first glimpse of this ‘delightful if eccentric’ mathematician.
Douglas Hofstadter’s elegant bestseller Gödel, Escher, Bach: An Eternal Golden Braid, also
published in 1979, put the Turing test and the Church–Turing thesis onto many a coffee table.
Another 1979 book, The Mighty Micro, by the National Physical Laboratory’s Christopher Evans,
contained significant coverage of Turing’s work, as did Simon Lavington’s more specialized Early
British Computers the following year. Gordon Welchman’s 1982 The Hut Six Story: Breaking the
Enigma Codes told much about Turing, and so did Andrew Hodges’ classic 1983 biography
Alan Turing: The Enigma. Several 1984 books on the computer revolution dwelt on Turing: Stan
Augarten’s Bit by Bit, Joel Shurkin’s Engines of the Mind, and Michael Shallis’s The Silicon Idol.
Brian Carpenter and Bob Doran, the first computer historians to emphasize that the stored-
program concept originated in Turing’s ‘On Computable Numbers’, had written a landmark
article in 1977 (‘The other Turing machine’, in The Computer Journal), and in 1986 they pub-
lished their book A. M. Turing’s ACE Report of 1946 and Other Papers. This collected together
for the first time key materials explaining Turing’s role in computer history. In 1988 Rolf
Herken’s monumental The Universal Turing Machine: A Half-Century Survey was published;
and in 1989 Roger Penrose’s The Emperor’s New Mind: Concerning Computers, Minds, and the
Laws of Physics brought talk of Turing machines to dinner parties around the world.
In the following decade, Mary Croarken’s 1990 book Early Scientific Computing in Britain
gave good coverage of Turing and his ideas, as did David Kahn’s Seizing the Enigma (1991),
Doron Swade and Jon Palfreman’s The Dream Machine: Exploring the Computer Age (also 1991),
and Jack Copeland’s Artificial Intelligence (1993). George Dyson’s Darwin Among the Machines