Plato was the innovator of thedialogueanddialecticforms in philosophy, which originate with him. Plato appears to have been the founder of Westernpolitical philosophy, with hisRepublic, andLawsamong other dialogues, providing some of the earliest extant treatments of political questions from a philosophical perspective. Plato's own most decisive philosophical influences are usually thought to have been Socrates,Parmenides,HeraclitusandPythagoras, although few of his predecessors' works remain extant and much of what we know about these figures today derives from Plato himself.

TheStanford Encyclopedia of Philosophydescribes Plato as " of the most dazzling writers in the Western literary tradition and one of the most penetrating, wide-ranging, and influential authors in thehistory of philosophy. ... He was not the first thinker or writer to whom the word “philosopher” should be applied. But he was so self-conscious about how philosophy should be conceived, and what its scope and ambitions properly are, and he so transformed the intellectual currents with which he grappled, that the subject of philosophy, as it is often conceived—a rigorous and systematic examination ofethical,political,metaphysical, andepistemologicalissues, armed with a distinctive method—can be called his invention. Few other authors in the history of Western philosophy approximate him in depth and range: perhaps only Aristotle (who studied with him),AquinasandKantwould be generally agreed to be of the same rank.”