 MM faces two serious objections: the charge that it is self-refuting and the charge of solipsism. The charge of being self-refuting (or peritrope, as the ancients called it: literally, the charge of turning oneself upside down) was apparently formulated for the first time by Democritus (80A15 DK) and then further developed by Plato (in Theaetetus and Euthydemus) and Aristotle (in the fourth book of Metaphysics). In brief, this accusation states that if all judgements are true (this being the implicit meaning of MM), then the judgement that MM is false is also true; hence, MM is false. Protagoras had reportedly further claimed that “it is not possible to contradict” (80A19 DK) and this had led Plato and especially Aristotle (Met. IV 5, 1009a6–16) to add that the sophist denied the principle of non-contradiction, suggesting another version of the peritrope charge: Protagoras claims that all judgements are true (let us call this thesis P) and his opponent that Protagoras’ claim is false (non-P); but according to Protagoras contradiction is impossible and therefore non-P is compatible with P; but in this case, non-P is true; hence, P is false (Barnes 1979: 548).