UBC Theses and Dissertations
Machines cannot think Gell, Robert George
This paper is a critical essay on the question "Can machines think?", with particular attention paid to the articles appearing in an anthology Minds and Machines, A. R. Anderson editor. The general conclusion of this paper is that those arguments which have been advanced to show that machines can think are inconclusive. I begin by examining rather closely a paper by Hilary Putnam called "Minds and Machines" in which he argues that the traditional mind-body problem can arise with a complex cybernetic machine. My argument against Putnam's is that either there are no problems with computers which are analogous to the ones raised by mental states, or where there are problems with machines, these problems do not have at bottom the same difficulties that human experiences raises. I then continue by showing that a cybernetic machine is an instantiation of a formal system. This leads to a discussion of the relationship between formality and predictability in which I try to show that some types of machine are in principle predictable. In the next section I attempt to prove that any discussion of outward signs of imitative behavior presupposes that some linguistic theory, such as a type reduction, has been substantiated. The force of this argument is that such a theory has not in fact been substantiated. I offer some general theory about the complexity of concept-property relations. Finally I give a demonstration that no test or set of tests can be found that will be logically sufficient for the ascription of the concept "capable of thought." If this is successful, then I have shown that no test can be found, which when a machine is built to pass it, is logically adequate for saying that that .machine can think. This argument is offered as further criticism of the Imitation Game which A. M. Turing proposed as an adequate test for thinking subjects. Besides the specific conclusion that insufficient evidence, has been offered to say that machines can think, this paper offers a more general conclusion that most standard problems have at bottom a linguistic difficulty. However, this general conclusion is a broad speculative one to which the work in this paper, is only a small exemplification and as such reflects mainly the further ambitions of the author.