Elenchos come Petitio Principii

The paper argues that the elenctic argument in defence of the Law of Non-contradiction is a Petitio Principii. In the first part of the paper, Emanuele Severino's development of an elenctic strategy in Ritornare a Parmenide is examined and compared with Graham Priest's defence of the truth of some contradictions. The fundamental reason why the elenctic strategy begs the question is that, in order to work, it presupposes exactly that account of negation which is challenged by the friends of contradictions like Priest. In the second part, the traditional idealistic argument against the existence of the 'Thing in itself' is shown to suffer from the same problem.