Greek dream interpretation and the Oneirocritica

Artemidorus of Daldis was a working diviner in Roman Asia Minor in the second century CE. He was from Ephesus and took his surname from Daldis, his mother's town in Lydia. He wrote five books: the first three for the public, the last two privately for his son, who was starting out in the same trade. He says he assembled the material by travelling through Greece, Italy and Asia collecting dreams and their outcomes from diviners of every station, and he names sixteen predecessors whose books are now entirely lost. His is the one that survived.

The first thing the book does is throw most dreams away. Artemidorus separates the oneiros, which he holds to indicate something to come, from the enypnion, which merely reflects the state the dreamer is already in: you dream of eating because you went to bed hungry, of being pursued because you are frightened. Only the first is worth interpreting, and he is clear that it is the rarer of the two. A framework in which most dreams mean nothing is the opposite of a dictionary in which every dream means something.

He then divides what is left. A theorematic dream comes true as shown, and he gives the example of a man who dreamt of a shipwreck and was shipwrecked, which needs no interpreter. An allegorical dream signifies one thing by means of another, and that alone is what the manual is about. His stated method is disarmingly plain: interpretation, he says, is nothing other than the juxtaposition of similarities.

The move that separates him from everything written since is that he treats the dreamer as part of the dream. The same image is expected to read differently by status, occupation, wealth, health, age and habit, and he instructs his son to ask about all of them before saying anything. He gives the case bluntly: to dream you are made of gold means one thing for a slave, another for a poor man, another again for a rich one. A dictionary that gives an image a single meaning has thrown away the part of the method that did the work.

The book sits on an older Greek layer that had already taken a position. Homer had Penelope describe two gates through which dreams reach us, one of horn and one of sawn ivory, and only those through the horn come true. That is the earliest surviving statement in European literature that some dreams deceive, and it is a warning rather than an invitation. Alongside the interpreters ran two quite different practices: incubation, in which the sick slept at a sanctuary of Asclepius in the expectation of a dream that would heal or prescribe, and the Hippocratic reading of dreams as diagnostic signs of imbalance in the body. Aristotle, meanwhile, wrote that dreams have natural causes and that most apparent prophecy is coincidence.

None of this made it into the modern genre. What survived was the symbol list, stripped of the classification that discarded most dreams, of the scepticism, and of the insistence on knowing who was dreaming. The lists you find online are downstream of Artemidorus with everything that made him careful removed.