Christopher Strachey (1916-1975) was a British computer scientist whose papers and correspondence are held by the Bodleian Libraries at Oxford, the primary source used here. A friend of Alan Turing, Strachey first taught himself programming on Turing’s machines and went on to become a major figure in programming-language theory, eventually founding the Programming Research Group at Oxford and, with Dana Scott, developing denotational semantics, a rigorous mathematical way of defining what programs mean.
In the prehistory of artificial intelligence he is remembered for two early experiments on the Ferranti Mark 1 at Manchester. In 1951 he wrote a program to play draughts (checkers); having obtained the machine manual from Turing, he transcribed and expanded his code so that by the summer of 1952 it could play a complete game at a reasonable speed, making it one of the earliest programs to play a full board game. That same summer he wrote a love-letter generator that assembled sentimental messages from a small vocabulary using a simple template and random choice, producing what is often called the first piece of computer-generated literature.
Strachey matters because his playful programs probed, very early, the question of whether activities tied to human intelligence and even human feeling, strategic game play and the writing of a love letter, could be carried out by a machine following rules. The draughts program tackled reasoning and search; the love-letter generator tackled the mechanical production of seemingly creative text, a distant ancestor of today’s generative language systems.
For a general reader, Strachey is a reminder that the question now raised by chatbots, whether a machine churning through rules can produce something that feels human, was being explored, with humor, more than seventy years ago.