The recently mooted theory that Andy Warhol was mildly autistic is oddly plausible. Still, Pop was the culture of the 1960s, and Warhol was not only the definitive Pop artist, who became an icon in his own right, but an influential presence on succeeding generations of artists and other assorted wannabees. His studied blankness concealed . . . well, nothing really. With Warhol, what you saw was what you got. Like Dali, he realised that culture was an industry and that marketing yourself was the way to go, and people like Jeff Koons and Damien Hirst were paying attention. His work of the 1960s, mass-produced images of mass market banalities, like Campbells soup cans or Coke bottles, or the rather more grim tabloid press photos of car crashes and electric chairs, had a raw energy that was dissipated through repetition and self-parody, but his celebrity, and his exemplary importance, haven't yet faded.