Pamela McCorduck first went among the artificial intelligentsia when the field was fresh and new, and asked the scientists engaged in it what they were doing and why. She saw artificial intelligence as the scientific apotheosis of one of the most enduring, glorious, often amusing, and sometimes alarming, traditions of human culture: the endless fascination with artifacts that think. Machines Who Think was translated into many languages, became an international cult classic, and stayed in print for nearly twenty years. Now, Machines Who Think is back, along with an extended addition that brings the field up to date in the last quarter century, including its scientific and its public faces. McCorduck shows how, from a slightly dubious fringe science, artificial intelligence has moved slowly (though not always steadily) to a central place in our everyday lives, and how it will be even more crucial as the World Wide Web moves into its next generation.