Some people say that Bruce Nauman is the most influential American artist since Andy Warhol,but when Nauman arrived at art school in 1964,he had almost no idea where he was headed. The tall,laconic young Nauman painted the most mundane of subjects: landscapes. I thought art was just something Id learn how to do,and then I would just do it, he says. Hed landed at the University of California,Davis,home to the most rebellious,irreverent artist-teachers around. The faculty gave Nauman an empty room in a temporary building and told him simply to go to work. I knew then, he says,that Id have to start out every day and figure out what art was going to be. From then on,with each and every work hes made,Nauman has started back at square one. One time he cast a part of a female body,from fingertip up the arm to the lips,and called the resulting wall sculpture From Hand to Mouth (1967). Another time,he made Green Light Corridor (1971): two high free-standing walls,illuminated from above with bilious fluorescent light,and placed less than two feet apart to test viewers tolerance of claustrophobia. On big public projects,such as filling the enormous Turbine Hall at the Tate Modern museum in London in 2004,hes used sound,including a menacing recorded voice saying,Get out of this room,get out of my mind. For the Venice Biennale,where Nauman,67,is the official US representative this year,he has wrapped the top of the modest,bank-like American pavilion with words such as lust and prudence,denoting various vices and virtues blinking on and off in a rainbow frieze of neon. What separates Nauman from his hundreds of imitators is his deep-down,plain old hand-to-paper artistic talent. Nauman draws constantly,from loose diagrams through precise linear renderings to big,expressionist architectural fantasies. But he probably could not have become this influential if he hadnt entered the art world from left field and always remained a bit of an outsider.