Everyone thinks they know what satire is, or, at least, what is meant by ‘satire’. But this knowledge is a dangerous thing. It conceals the fact that the term ‘satire’ has two meanings. For us, it denotes a tone of voice which may occur in virtually any form – a novel, a letter, a play, a cartoon, a comic sketch. But for the Romans it denoted a specific form of literature, the two literary genres of satire, Roman verse satire and prose ‘Menippean’ satire. Strict rules governed the form and content of these literary genres; these rules emerge from the study of the satires which survive. Yet both genres are recognizable as satire and it is clear that modern theories about the origin and nature of satire apply with equal validity to Roman satire. In this introduction I shall attempt to present a few of the most significant of the modern approaches to satire.