Peritrope
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Peritrope was known for many centuries primarily as a tool for refuting ancient skepticism (in Sextus Empiricus, Avicenna, and Thomas Aquinas, for example). If I make the assertion, “There is no truth,” then you can respond using peritrope by posing the rhetorical question “Well, then, isn’t that true?” It is often known as the accusation of ‘self-refutation.’ The word itself is Greek for "turning around".
First formally identified by Sextus Empiricus in a discussion of Socrates’ refutation of Protagoras, Peritrope has a long and surprisingly contiguous history in philosophy. Since peritrope is, put simply, the accusation that a philosopher has retained what he has disavowed in and by the disavowal itself, peritrope has an immediate bearing on all questions concerning the possibility of any totalized overcoming or transcendence in general. Despite this, peritrope has received only limited academic attention in recent years (mostly in the work of Barbara H. Smith, Carl Page, and Myles Burnyeat).
You can find Socrates refutation of Protagoras in Plato's Theatetus; starting around 169 and continuing till around 171e. In the book titled "What Plato Said", the author Paul Shorey states: "The first argument advanced by Socrates is the so-called peritrope, to use the later technical term, that the opinion of Protagoras destroys itself, for, if truth is what each man troweth, and the majority of mankind in fact repudiates Protagoras' definition of truth, it is on Protagoras' own pragmatic showing more often false than true"
