The dissertation treats Plato’s early philosophy which, unfortunately, till now didn’t receive due attention in Lithuanian scholarship. From the nineteenth century a belief dominates among scholars that so-called “theory of ideas” is a foundation of Platonic philosophy and that ethical, epistemological and ontological issues are considered on the basis of this “theory”; although the latter was explicitly formulated only in the dialogues of the middle period, scholars believe that even doctrines which took shape in the “Socratic” dialogues presupposes the assertion of the existence of “pure forms”. In the dissertation this stereotype is discarded and, following Vlastos’ ideas, an alternative perspective of the interpretation of dialogues is proposed. In this case, the originality of Platonic philosophy is related with a specific methodic of the philosophical investigation, not with certain general “idealistic system”. First of all, we focus on the method of elenchus which Vlastos describes as a device (constantly used by Socrates, the main character of the dialogues) to refute interlocutor’s primary thesis, demonstrating its inconsistency with his other beliefs. However, from the point of view of logic, this method isn’t unproblematic: according to Vlastos, elenchus does not confine strictly to the refutation and can provide positive results, but it is evident that the value of its results depends on the veracity of its premises (because elenchus is deductive reasoning), nevertheless Socrates doesn’t give distinct criteria for choosing them. That’s why in some cases elenchus resembles sophistic technique of contest. In the dissertation other important methodological and epistemological aspects are considered: “the priority of definition principle”, “the doxastic constraint”, the idea of knowledge as a systematic whole, application of the “mathematical” method of hypothesis in the ethics, the role of the “theory of ideas” as a hypothesis.

Raktažodžiai: Greek philosophy, method, knowledge, elenchus