Franz Brentano (1838-1917) led an intellectual revolution that sought to revitalize German-language philosophy and to reverse its post-Kantian direction. This volume brings together newly commissioned chapters on his important work in theory of judgement, reform of syllogistic logic, theory of intentionality, empirical descriptive psychology and phenomenology, theory of knowledge, metaphysics and ontology, value theory, and natural theology. It also offers a critical evaluation of Brentano's significance in his historical context, and of his impact on contemporary philosophy in both the analytic and the continental traditions.