The best lectures I had at Columbia--among many competitors--may well have been Richard Wollheim's aesthetics lectures, in which he walked us rather philosophically naive undergraduates through his own theory of criteria for the identity of artworks. He was incredibly patient in his attempts to grasp what exactly we failed to understand--which for most of us was most of what he had to say. What shone through for us in any case was his brilliance and the careful insight that went into his philosophical writings, re-enacted before our eyes in the classroom. All this inspired a number of us to re-read his work with greater attention and, we hoped, come away with a better grasp of the Wollheimian view and how to challenge it. As someone who now writes on aesthetics, I look back on the experience as inspiring and provocative.