When is a performative contradiction not a contradiction? When the ‘performative contradiction’ objection is a tu quoque fallacy.
So what is a performative contradiction? We need look no further than Matt Stone and Trey Parker’s Team America: World Police to answer this question. Hollywood actor Gary Johnston (the Tom Cruise parody) is approached by Spottswoode, a United States Government agent, to join the Team America forces. Spottswoode proposes that Gary meet the rest of the team. Gary agrees; Spottswoode and Gary get into Spottswoode’s limousine to make their way to Team America headquarters. But to Gary’s surprise the limousine doesn’t drive, it flies. This is the dialogue that ensues:
Gary Johnston: OK, a limousine that can fly. Now I have seen everything.
Spottswoode: Really? Have you seen a man eat his own head?
Gary Johnston: No.
Spottswoode: So then you haven’t seen everything.
And Gary will never see a man eat his own head because to eat one’s head is impossible. A man simply cannot eat his own head for one good reason: the mouth is a part of the head. So to eat all of one’s head one would have to eat one’s mouth. But how can one eat one’s mouth with one’s mouth? You may get the lips down, but that’s about it. Once you get to the teeth and jaw, you’re done. At this point anyone who tries to do this will realise that he’s engaged in a performative contradiction. (No doubt dejection would follow.) Insofar as we maintain that eating involves chewing and to chew we need to have a mouth, including teeth and a jaw, then there comes a point when you cannot eat any more of your head because the very apparatus required for eating are part of the head.