Ernst Laas, the German philosopher, was born in Förstenwalde. From 1872 on, he was professor in Strasbourg. His first important book, Kants Analogien der Erfahrung (Berlin, 1876), was a critical study both of Immanuel Kant and of "the foundations of theoretical philosophy"; but in his main work, Idealismus und Positivismus (3 vols., Berlin, 1879–1884), he launched a general attack on idealism, including Aristotle, René Descartes, Gottfried Wilhelm Leibniz, and especially Plato as its founder, as well as Kant. His purpose was to provide a remedy for the "discontinuity of philosophy"; that is, its failure to make progress over the centuries and its want of any clear standards. The remedy lay first of all in a new critical approach to the history of philosophy, which in the past had usually been at best merely scholarly and accurate. This new analysis revealed a basic dualism throughout the history of...