“HIs chess-playing methods did the same thing — as did the games on the Colossi — and posed the question as to where a line could be drawn between the 'intelligent' and the 'mechanical'. His view, expressed in terms of the imitation principle, was that there was no such line, and neither did he ever draw a sharp distinction between the 'states of mind' approach and the 'instruction note' approach to the problem of reconciling the appearance of freedom and of determinism.”