This lecture explains some key concepts necessary to our examination of the Athenian philosopher Socrates. In the first of the lecture’s two parts, we discuss the idea of “philosophy,” especially in its relation to nature; the pre- Socratic efforts to discover the deepest cause responsible for the generation and existence of all things, be it atoms and void or some combination of fundamental elements (such as, earth, air, water, and fire); the necessary conflict between such philosophical inquiries and the authoritative explanations of the world that rely on the gods; and Socrates’s characteristic turn away from scientific speculation and toward a conversational analysis of “the human things,” or moral-political questions. In the second part, we discuss some characteristic features of ancient Greek comedy in general and Aristophanic comedy in particular, with specific attention to the comedy Aristophanes himself singled out as being his “wisest” work, the Clouds.