 Beyond their (presumed?) usefulness in teaching argumentative skills, the literature on fallacies raises a number of important philosophical discussions, such as: What determines when an argument is fallacious or rather a legitimate argument? (See  section 4.3  below on Bayesian accounts of fallacies) What causes certain arguments to be fallacious? Is the focus on fallacies a useful approach to arguments at all? (Massey 1981) Despite the occasional criticism, the concept of fallacies remains central in the study of arguments and argumentation.