Badiou insists that philosophy is the discipline concerned with truth, and that any effort to detract philosophy from this concern is tantamount to sophistry.

It means that the philosopher must find a different way to be faithful to Plato’s insistence on a truth that is superior to mere doxa. If we put this in Platonic terms, the philosopher’s task is to transcend the marketplace of opinions (doxa) and appeal to universal truths that hold sway in any given context.

The argument is that, if statements can only produce effects to the extent that they have force in a language game, then the statements of philosophy have no special import. If so, then there is no hope of reorienting the rules of language games to prioritize, for example, the scientist's statements on global warming over those of the chat room fool, or the doctor's statements on illness over those of the quack. Hence the importance of truth to philosophy.

It is the negative conception of sophists that concerns me. As I understand it the sophists largely concentrated on teaching rhetoric and training the young politicians to persuade the multitude with a series of stock arguments.

Rhetoric is then given a particular twist. Sophists are seen to entangle, entrap, and confuse their opponents, by means of strange or flowery metaphors, by unusual figures of speech, by epigrams and paradoxes, and in general by being clever and smart.

The sophists had little concern with a concern for the truth as they used fallacious arguments knowing them to be such.