Performative contradiction are performative contradictions in this context. Habermas claims that post-modernism's epistemological relativism suffers from a performative contradiction. Hans-Hermann Hoppe claims in his theory of argumentation ethics that arguing for any political position other than free-market anarchism results in a performative contradiction. Jaakko Hintikka more rigorously fleshed out the notion of performative contradiction in analyzing Descartes' famous "cogito ergo sum" argument, concluding that "cogito ergo sum" relies on performance rather than logical inference. Performative contradiction A performative contradiction () arises when the propositional content of a statement contradicts the presuppositions of asserting it. An example of a performative contradiction is the
Cogito, ergo sum itself is good and pleasant (...) and if one who sees is conscious that he sees, one who hears that he hears, one who walks that he walks and similarly for all the other human activities there is a faculty that is conscious of their exercise, so that whenever we perceive, we are conscious that we perceive, and whenever we think, we are conscious that we think, and to be conscious that we are perceiving or thinking is to be conscious that we exist... ("Nicomachean Ethics", 1170a25 ff.) Augustine of Hippo in "De Civitate Dei" writes "Si […] fallor, sum"