From the Iliad onwards, via Aristophanes and the gospel of Matthew, to Augustine and beyond, Greek and Latin texts in many genres are constellated with dream-descriptions. The best ancient minds, Plato, Aristotle and Galen among others, paid careful attention to what dreams might mean. Yet no work in English (and only one in any other language) attempts to establish how the Greeks and Romans understood their dreams. In Dreams and Experience in Classical Antiquity, I make cultural history out of this material, with the help of contemporary post-Freudian science.I contrast Greek and Roman ways of understanding dreams with those that prevail in the modern west, while contradicting the opinion that the Greeks and Romans in general treated their dreams superstitiously and credulously (sometimes they did, just as people do now).I start with “epiphany” dreams, a type of dream still sometimes described in unmodernized societies: these are dreams consisting of “appearances” by authority figures who give orders or impart information. I explore the psychological, religious and literary reasons why this form of dream-description was so popular, trace its continuance through the Middle Ages and attempt to explain why it has virtually died out.Did ancient people really dream like that? This question leads to another: can we ever know what any ancient person really dreamt? A number of extraordinary individuals feature in this discussion, including Saint Perpetua and the emperor Constantine. But the person who comes out of the investigation best is the hypochondriac second-century AD rhetorician Aelius Aristides, author of what is in effect antiquity’s only surviving dream diary.Did the Greeks and Romans then believe in their dreams? What that might mean, and how Greeks and Romans of different classes and periods differed on this subject, are questions that require a careful analysis. In the book, this ranges from the relative credulity of Artemidorus of Daldis, the author of Graeco-Roman antiquity’s only surviving dream-book, to the lucid scepticism of Cicero. This is mainly an investigation of ordinary people; my last chapter by contrast assesses Greek and Roman attempts to understand dreams naturalistically. In other words the chapter is about the efforts of philosophers and physicians, some of whom – most notably Aristotle – made a large number of perceptive statements about a phenomenon, which as far as dream-content is concerned, still remains mysterious.