To dream of being beheaded, of being turned to bronze, of blowing a sacred trumpet, of riding a horse through the city, of becoming a king, of flying – these were just a few of the dreams that Artemidorus took to signify that the slaves who dreamed them would at some future point in their lives be set free. There was always a good reason: beheading indicated the impending separation of slave and slaveowner; it was only the free who had bronze statues set up to them, only the free who possessed sacred trumpets and had the privilege of riding through the city on horseback; a king had to be free by definition, and to fly was to resemble a bird, a creature above which there could be no other. This was not all fancy. A slave known to Artemidorus was actually manumitted after dreaming that he had three penises, exchanging his single name for the three names of a Roman citizen. Artemidorus’ science was not to be doubted.

The interpretation of slaves’ dreams was predicated on the dual assumption that freedom was the greatest benefit that could be bestowed on the slave and that it was a benefit the slave unquestionably wanted to acquire. At one stage indeed (Onir. 2.3) Artemidorus speaks of slaves who longed for freedom.