This study proposes a revaluation of the rhetoric of Gorgias. He has been accused of developing a rhetoric of 'what is not', a rhetoric which aims not at truth but at falsity. The revaluation gives full weight to the central conception of tò eikós and contends that Gorgias' rhetoric is in principle rationally grounded in 'the nature of things'.
Chapter I sets Gorgias against his background, arguing that he occupies a position between nominalism and realism, and between sensationalism and intellectualism. Chapters II and III consider the theoretical bases of his rhetoric, first in the epistemological section and then in the linguistic section of On What is Not. Chapters IV and V, taking their start from On What is Not and also from the Defence of Palamedes, attempt to unify the rhetorical and the philosophical aspects of the two essays. Finally, Chapter VI suggests that four of the five causes canvassed in the Encomium to Helen depend on Euripides' Trojan Woman, while the fifth relies on his Helen (and thus explains Gorgias' title).
This work intends to detect in Gorgias all those rational elements rotating on the function of the verisimilar, in order to determine more precisely both the constitution of his rhetoric and his position as an intellectual in the forefront in the culture of his time.