Some questions are like a cavity in a tooth; we keep coming back to probe them over and over until our tongues grow raw on their jagged edges. My topic is one of these.  It has been explored almost without intermission for three hundred years. No one could estimate how many learned essays and lectures have been devoted to it. Dozens of articles and books sharing the generic titles, Minds, Machines, and Other Things are appearing daily. The pace at which these works are produced has grown in direct ratio to the complexity of the machines we can construct, which is to say that there has been an enormous outpouring of them in the last decade or two. The irritant for this recent outbreak of probing, of course, has been the emergence of automatic computing machines as a major influence in our lives. These new machines have enormously enlarged our conception of what a machine can be and do, and with every such enlargement it seems necessary to consider once again the ancient problem of the relation between men and machines.