Early warnings about the risk from AI were rather vague. Turing himself, in a 1951 radio address, felt it necessary to point out the risk from superintelligent AI: "If a machine can think, it might think more intelligently than we do, and then where should we be? Even if we could keep the machines in a subservient position, for instance by turning off the power at strategic moments, we should, as a species, feel greatly humbled. I. J. Good adds to his prediction of the benefits of an intelligence explosion the proviso, "provided that the machine is docile enough to tell us how to keep it under control." One has a general sense that the presence of superintelligent entities on our planet might be cause for concern; on the other hand, we generally find that smarter machines are more useful so it is not obvious why making them very much smarter is necessarily bad.