Sigmar Polke has a lot in common with the medieval alchemists with whom he identifies. Like them, he is interested in transmutation, sometimes employing pigments and techniques that make his paintings change over time. Like those pseudo-scientists of the past, he uses a combination of mystification and explanation to lure the public and patrons. And just as the charlatanry of alchemy led to frequent breakthroughs in the science of chemistry, Polke's often confusing work reveals glimpses of the imaginary philosopher's stone of "true art."

Recognized along with Gerhard Richter and Anselm Kiefer as one of the greatest German postwar artists, Polke was recently in Tokyo for an exhibition of his art at the Ueno Mori Museum as part of "Deutschland in Japan 2005/06."

Throughout his long career, the 64-year-old artist has managed to defy categorization by occupying the space in art between the figurative and abstract, organic and artificial, and highbrow and lowbrow. He is also renowned for giving art critics a tough time, talking in riddles with a heavy German accent and refusing to answer questions about his private life.