Jonathan Ketchum

This dissertation is the documentation of a discovery that most of the Plato dialogues generally considered authentic are composed according to the dictates of one and the same structure. It is comprised of an introduction , and three main sections named the protrepsis, the incursion, and the exegesis. In addition, a principle of internal tripartition is in play, such that each main section excepting the incursion is subdivided into three sections, which in turn are again subdivided into three subsections, which are again usually further so subdivided. The incursion section is divided into two parts, each of which is further subdivided as above. ;While the tripartite structure is often obvious, whatever significance it may have is not so clear. The significance of the main sections, while varying some from one type of dialogue to another, is much clearer. The introduction gives concrete exemplification of the more abstract ideas drawn out of it in the main dialogue. In the protrepsis, a prevailing way of thinking about a philosophical topic is presented and, in the earlier dialogues, refuted. In the incursion, philosophical considerations unusual for the times are introduced, so as to put the substance of the protrepsis in an altogether new light. Socrates grasps the import of this convention-shattering development, but the respondent does not. In the exegesis, the main protagonist is shown airing the consequences of the new philosophical grounding of the issue in question, while the respondent insulates himself from that understanding and sinks back into his former ways. In general, the dialogue between protagonist and respondent represents a dialogue between philosophically and sophistically disposed persons on the issue at hand. ;The dissertation itself is in four parts. In the General Introduction, the structure and interpretation resulting from structural understanding are discussed in detail. The Crito, Parmenides, Timaeus, and Laws are shown to be significantly incomplete--a fact having considerable bearing on their interpretation. The Menexenus is seen to be a work of significantly different structure. Problems with the structure of the Cratylus are discussed. The Hippias Major is shown to be structurally complete and regular, and the Alcibiades I almost so. This work may have some bearing on determination of authenticity. The General Introduction ends with discussions of the subsequent fate of dialogue structure, and on the theme, Plato today. ;In the second section of the dissertation, the turning points between the first two and second two sections of all the dialogues are established. In the third section, all the introductions are discussed in detail, and grouped by types. In the fourth section, all the protrepses are also so treated. The work of detailed analysis of the incursion and exegesis sections, as well as the turning points between them, remains to be done