In 1998 The Brentano Puzzle, edited by Roberto Poli, was published. This collection, the proceedings of a conference by the same name, posed the question of Franz Brentano's importance to philosophy. Yet, the idea behind the conference was to work through the puzzle that surrounds Brentano's apparent invisibility as a nineteenth-century thinker. There seems to be no doubt about his intellectual legacy into the twenty-first century: his scholarly work in both philosophy and psychology is profoundly influential. His place as an esteemed twentieth-century cultural theorist is guaranteed by what now might be thought of as his cross-disciplinary contributions through his passionate engagement in the intellectual life of the late nineteenth century. Brentano is rarely mentioned as a great philosopher of that century, however, in spite of his philosophical significance. Whether that significance should be couched in terms of his philosophical contributions as a thinker in his own right or...