Everyone knows about the Turing Test. It was first proposed by Alan Turing in his famous 1950 paper'On Computing Machinery and Intelligence'. The paper started with the question'Can a machine think?'. Turing noted that philosophers would be inclined to answer that question by hunting for a definition. They would identify the necessary and sufficient conditions for thinking and then they would try to see whether machines met those conditions. They would probably do this by closely investigating the ordinary language uses of the term'thinking' and engaging in a series of rational reflections on those uses. At least, Oxbridge philosophers in the 1950s would have been inclined to do it this way. Turing thought this approach was unsatisfactory.