The threshold between a machine which was the intellectual inferior or superior of a man would probably be reached if the machine could do its own programming.
I. J. Good, Review of D. R. Hartree, Calculating Instruments and Machines, Journal of the Royal Statistical Society. Series A (General), vol. 114, no. 1 (1951), p. 107
Once a machine is designed that is good enough, […] it can be put to work designing an even better machine. At this point an “explosion” will clearly occur; all the problems of science and technology will be handed over to machines and it will no longer be necessary for people to work. Whether this will lead to a Utopia or to the extermination of the human race will depend on how the problem is handled by the machines. The important thing will be to give them the aim of serving human beings.
I. J. Good, “Speculations on Perceptrons and Other Automata”, IBM Research Lecture, RC-115 (1959), p. 17