This dissertation examines Socrates' method of examining interlocutors, referred to as the elenchus, in Plato's definitional dialogues. It contains three parts. The first part lays out various theories of the elenchus. The first chapter examines the seminal view of Richard Robinson. The second sketches the development and aftermath of Vlastos' constructivist view. The third focuses on Socrates' own testimony about the elenchus in the Apology. These pictures of the elenchus form a selection of views against which various definitional dialogues may be compared. The second part, containing six chapters, provides a detailed commentary on the Euthyphro. Various features of that dialogue suggest that neither the prominent forms of constructivism, nor their non-constructivist alternatives presented in the first part adequately capture Socrates' procedure. The third part, consisting of one chapter, presents my view of the Socratic elenchus, which I term “technical destructivism.” I argue that this view provides a straight-forward solution to a number of problems which the alternative treatments leave unsolved. It also helps to explain some otherwise puzzling features of Socrates' procedure in the shorter definitional dialogues, including his use of the technē analogy, and his appeal to the priority of definitional knowledge. / Philosophy / text