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 "Meditations", Descartes phrases the conclusion of the argument as "that the proposition, "I am, I exist," is necessarily true whenever it is put forward by me or conceived in my mind." ("Meditation" II) At the beginning of the second meditation, having reached what he considers to be the ultimate level of doubt—his argument from the existence of a deceiving god—Descartes examines his beliefs to see if any have survived the doubt. In his belief in his own existence, he finds that it is impossible to doubt that he exists. Even if there were a deceiving god (or an evil demon),