HARVARD UNIVERSITY’S COMMENCEMENT speaker this year was Harry Potter creator J.K. Rowling. If it seems surprising that a children’s author would stand on a podium previously occupied by Bill Gates and Kofi Annan, maybe it shouldn’t. Not just because the world’s richest author is a natural fit for the world’s richest university, but because deep parallels abound between Harvard and Hogwarts, the wizard boarding school at the heart of Rowling's invented universe. Both trade on a mystique borrowed from the traditions of British boarding schools; both boast their share of rituals and arcana.