This chapter's main purpose is to explicate Aristotle's theory of tragedy, taking stock of one of the most influential definitions of tragedy in public discourse, not only for its own sake but to explain how and why specific aspects of tragedy, namely the tragic hero, catharsis, and the flaw, became so widespread. It discusses each, drawing on interpreters, such as Jacob Bernays, Edmund Burke, and Samuel Weber, and culminates in a reading of Aristotle influenced by Martha Nussbaum, focusing on the fragility of human beings and its significance for thinking about “the individual” in modern social science.