Abstract
(1) The aim of the paper is to develop a reduction of fallacy theory, i.e. to 'deduce' fallacy theory from a positive theory of argumentation which provides exact criteria for valid and adequate argumentation. Such reductionism has several advantages compared to an unsystematic action, which is quite usual in current fallacy but which at least in part is due to the poor state of positive argumentation theory itself. (2) After defining 'fallacy' (3) some principle ideas and (4) the exact criteria for (argumentatively) valid and adequate arguments of the 'practical theory of argumentation' of the author are expounded. These criteria will be used as the positive basis for the following reduction. (5) In the main part of the paper a systematization, definition and explanation of the main types and many subforms of fallacies of argumentative validity and (6) adequacy is developed, following the list of positive conditions of validity and adequacy. In addition to many new types of fallacies, this systematization contains the most important of the traditionally known and named fallacies; these are explained and the criteria for some of them are corrected or put more precisely