Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: Gwilym Owen wrote an article arguing a work by this man was written earlier than traditionally thought. Assumptions of self-predication and non- identity are necessary to an argument made by him according to an article by Gregory Vlastos. David Sachs said one of this man's arguments suffered from a fallacy of irrelevance by using two definitions for one of its main concepts. Gerard Ledger used a stylometric computer program to analyze this man's writings, which led Ledger to support the authenticity of a letter that describes this man's efforts to educate (*) Dionysius of Syracuse to be a good ruler. He claimed that for everything that exists there are three instruments for attaining knowledge, the knowledge itself, and a fifth "the thing itself which is known and truly exists" in his Seventh Letter. It's not his student, but this man introduced the Third Man Argument in his Parmenides. For 10 points, name this author of the Republic and other Socratic dialogues.
A:
Social Science