I first met Cog in July 1994, in Rodney Brooks’s Artificial Intelligence Laboratory at MIT. The institute was hostin g an artificial-life workshop, a conference that buzzed with optimism about science on its way to synthesizing what contributors called “the living state.” Breathtaking though they were in capturing many of the features of living systems, most of the “life forms” this field had developed had no physical presence more substantial than images on a computer screen; these creatures lived in simulation. Not so Cog, a life-size human torso, with mobile arms, neck, and head.
Cog grew out of a long research tradition in Brooks’s lab. He and his colleagues work with the assumption that much of what we see as complex ...