Why do humans (and even some animals!) laugh, and what is it that makes us laugh? What does laughter do, and how does it create social difference and cohesion? We will analyze and enjoy some of the world’s oldest jokes, compare them to what we find funny today, and investigate the evolutionary advantages of laughing. This course puts very old examples of humor (joke-collections and comic plays from ancient Greece and Rome) side by side with very new twenty-first century examples of humor proposed by you (memes, sitcoms, TikTok videos, standup comedy etc. etc.). By using ancient Greece and Rome as a fringe test case we will investigate whether there is such a thing as a universal, human sense of humor, and, if so, what it might be. Whenever we encounter unbridgeable gaps in humor appreciation, whether between us and “the ancients” or within our group, we will try to explain these gaps, and explore how they highlight human difference. In the same way we will read ancient theories about humor and laughter, and compare them with modern approaches to these phenomena from Cognitive Psychology, Evolutionary Biology, Sociology, and Philosophy. We will focus on how laughter has been used by theorists to define what it means to be human and to distinguish between humans and nonhuman beings. Finally, we will build on these theories and attempt to formulate answers to our central questions: why do we laugh, and what does laughter do?