Presented as a Vorlesung in the German philosophical tradition, this book presents the most detailed account of Nelsons method of argument analysis, celebrated by many luminaries such as Karl Popper. It was written in 1921 in opposition to the relativistic, subjectivistic and nihilistic tendencies of Nelsons time. The book contains an exposition of a method that is a further development of Kants transcendental dialectics, followed by an application to the critical analysis of arguments by many famous thinkers, including Bentham, Mill, Poincaré, Leibniz, Hegel, Einstein, Bergson, Rickert, Simmel, Brentano, Stammler, Jellinek, Dingler, and Meinong. The book presents a general theory of philosophical argumentation as seen from the viewpoint of the typical fallacies committed by anybody arguing philosophically, whether professional philosophers or philosophical laypeople. Although the nature of philosophy and philosophical argumentation is one of the most recurrent objects of reflection for philosophers, this book represents the first attempt at a general theory of philosophical fallacy. According to Nelson, it is in the shape of false dilemmas that errors in reasoning always emerge, and false dilemmas are always the result of the same mechanism--the unwitting replacement of one concept for another.

Introduction.- The dialectical illusion in philosophy.- On coherence and truth as properties of a philosophical system.- The logistic prejudice in the philosophy of the Schoolmen and in rationalism.- Kant overcomes the rationalistic prejudice: the distinction between analytic and synthetic judgments.-  The distinction between analytic and synthetic judgments further explored.- Significance and fruitfulness of the analytic-synthetic distinction.- Synthetic a priori judgments in geometry: the disjunction between logic and experience is incomplete.- Geometric logicism.- Geometric empiricism.