There may be occasions when it is best to behave irrationally, but whether there are should be decided rationally.
Good Thinking: The Foundations of Probability and Its Applications (University of Minnesota Press, Minneapolis, 1983), first paragraph
Let an ultraintelligent machine be defined as a machine that can far surpass all the intellectual activities of any man however clever. Since the design of machines is one of these intellectual activities, an ultraintelligent machine could design even better machines; there would then unquestionably be an 'intelligence explosion,' and the intelligence of man would be left far behind. Thus the first ultraintelligent machine is the last invention that man need ever make.