Abstract

J. R. Lucas serves warning that he stands ready to refute any sufficiently specific accusation that he is a machine. let any mechanist say, to his face, that he is some particular machine M; Lucas will respond by producing forthwith a suitable Gödel sentence ϕM. Having produced ϕM, he will then argue that — given certain credible premises about himself — he could not have done so if the accusation that he was M had been true. let the mechanist try again; Lucas will counter him again in the same way. It is not possible to accuse Lucas truly of being a machine.