In the Sophist Plato presents his mature views on sentences, falsehood, and not-being. These views have given an important contribution to the birth and growth of the subjects now identified as ontology and philosophy of language. I have two main objectives: to offer a precise reconstruction of the arguments and the theses concerning sentences, falsehood, and not-being presented in the Sophist and to gain a philosophical understanding of them. In this introduction I offer an overview of the main problems addressed in the Sophist and their solutions and then discuss the methodology whereby I pursue my primary goals.

The Main Problems Addressed by the Sophist and their Solutions

Purpose and structure. The Sophist, whose professed purpose is to define the sophist, has a nested structure, with a frame surrounding a core. The frame (216a1–236d4 and 264b11–268d5) endeavors to define the sophist by the method of division. The core (236d5–264b10) presents and solves some puzzles related to falsehood.