Machines Like Us

The symbol-manipulation paradigm for the mind spread like wildfire in the late 1950s. Formal logic in the tradition of Bertrand Russell dominated Anglo-American philosophy, with W. V. O. Quine as the dominant figure in America. Formalism reigned in mathematics, fueled by the Bourbaki tradition in France. Great excitement was generated by the Church-Turing thesis that Turing machines, formal logic, recursive functions and Emil Post's formal languages are equivalent. The question naturally arose: Could thought be characterized as a symbol-manipulation system?

The idea of artificial intelligence developed out of an attempt to answer that question, as did the information-processing approach to cognitive psychology of the 1960s. The mind was seen as computer software, with the brain as hardware. The software was what mattered. Any hardware would do: a digital computer or the brain, which was called wetware and seen (incorrectly) as a general-purpose processor. The corresponding philosophy of mind, called functionalism, claimed that you could adequately study the mind independently of the brain by focusing on the mind's functions as carried out by the manipulation of abstract symbols.

Read full review of Ray Jackendoff's book: Language, Consciousness, Culture: Essays on Mental Structure in American Scientist.