Artificial intelligence (AI), on the twenty-fifth anniversary of its naming, is a "kid, finally grown up." In this letter to his field, Feigenbaum recounts AI's stumbles and successes, its growing pains and maturation, to a place of preeminence among the sciences; standing with molecular biology, particle physics, and cosmology as owners of the best questions of science. Twenty-five years is not long in the history of a science--long enough to achieve, short enough to remember. Your esteemed founders are still around--vigorous, not so young anymore. Out of cybernetics you came, and information-theoretic psychology.

Artificial intelligence (AI), on the twenty-fifth anniversary of its naming, is a "kid, finally grown up." In this letter to his field, Feigenbaum recounts AI's stumbles and successes, its growing pains and maturation, to a place of preeminence among the sciences; standing with molecular biology, particle physics, and cosmology as owners of the best questions of science.