Dream incubation, or simply incubation, is a well known technique of ancient times, even if with local variations, due to different cosmogonies and theologies – more than because of different procedures.
Although modern simplifications show dream incubation as a very easy technique (oriented to methods aimed to implant a “seed” in the mind to dream about a specific topic, obtaining omens during the sleep-time), actually incubation praxis include a proper ritual, a dramaturgy not rarely based on elements characteristic of necromancy and the devotion to the (Mighty) Dead or Heroes.
This should not surprise, because in Ancient Greece (where this technique was widespread) Sleep was considered just another manifestation of Death, to which it was close and entwined. We’re referring to the twin brothers Hypnos and Thanatos, born from Nyx (the Night) and Erebus (the Infernal Darkness). They are the daemones of Sleep and Death, described by Homer in the XVI chant of the Iliad and by Hesion in the Theogony (758-766), as twins that dwell in the gloom of their mother Nyx, and “never upon them does Helios, the shining sun, cast the light of his eye-beam” (Hesiod, Theogony, 758 ff).
Often Hypnos and Thanatos are considered indistinguishable one from the other, except for one iconographic detail: Thanatos is represented with an inverted torch, whose reversed fire symbolize soul descending into the Underworld, the Life (or vitality) pasting from the body to begin a new journey.
Nevertheless, while Thanatos reaps the soul out from the body, Hypnos induces a certain state of being, and enters and exits from the body, giving birth to his many children: the Dreams (Oneiroi).
But there’s a moment when the power of the brothers is entwined and confused: the deep sleep, where, according to Greek sources, the spark of life is not. In this condition of complete abandonment, the soul can forget is Being and its Face (the Greek prósôpon/face or mask, from which, through the Etruscan pershu/mask, comes the Latin persōna/person). So the contact with the Divine is possible, through dreaming, and the Divine may manifest itself and be perceived, giving omens, blessing and cursing. Note that the process of forgetting of the mundane identity may be associated with or induce the possibility to hear the call of the Alien God – one of which offspring is Moros (sibling of Thanatos, Hypnos and the Keres, and just another mask through which Greeks represented the many faces of the primordial and anticosmic Chaos): he who’s called Theos Panôlethros, or the All-Destroying God who “even in the realm of Death, does not set his victim free” (Promētheús Desmṓtēs by Aeschylus).
Nevertheless the word incubation includes a strict relation with the idea of the bowels of the earth, the Underworld or Inferna (the lower region, from infernus as intensive of inferus denoting a particularly inferior spatial position). Indeed incubate is in-cubate, id est literally “to lie on”, “to rest on”, “to lye upon eggs” and even “to hatch an egg”. Aside the image of “brooding inside”, also the image of “lying upon” is peculiar and full of meaning, because it is directly referred to the Roman incubus, which act alike of Greek kakodaimonos (evil spirits). In Roman folklore, and not rarely in others too (see for example the Germanic or Slavic mare), incubus are depicted lying upon sleeping women and men to engage them in sexual activity and/or oppress them with dreadful dreams.
In the Greek world, incubation is strictly related to necromancy and the Chthonic Deities, at the point that exclusively the priestly caste of Asclepius was allowed to administer and admit to the learning of this praxis. Indeed dream incubation was officially performed only in the Asclepeion (the temple of Asclepius), and unofficially performed by sorcerers in those temple having chthonic hypogea consecrated to the veneration of certain Heroes, whose souls, even dwelling in the Elysium, maintained the role of intermediaries between the Mortals and the Divines, fulfilling the function of messengers. (Asclepius too was originally worshiped as an Hero in Trikka.)
Similarly, dream incubation performed out of the Asclepeion was considered as a heroic action, as well as the nekuia (the descent to the Dead, referred by Diodorus Siculus), the psychagogía (the evocation of the soul from the Underworld, as in Philostratus, that also use the term hērōicus to describe the performer of the ritual), the katabasis (the descent of the living into the Underworld where the dead dwell, as in Odyssey or in Orphic myths) and the necromancy (the divination through the reanimation of the corpse, widely found in Greek literature), all linked by some characteristic traits.
Concerning Asclepius, even if he was accounted as a minor deity, its genesis is remarkable.
Apollo fell in love with the mortal Cronis and, after consuming their love, he left a white raven to watch over her so she wouldn’t have any other lovers. However, since Apollo was slow to return to her, Coronis married Ischys, and with him she conceived a child. Then the white raven flight to Apollo revealing the betrayal, and the God punish it turning its wings black as the darkest night, because it has not fulfilled the assigned task. For avenge the insult suffered by his beloved brother, Artemis shoot an arrow, killing Coronis, that accepted her punishment expressing sorrow for her unborn child. Apollo, moved to pity, decided to salve her child cutting her belly to bring him to life.
In fact, the name Asclepius probably means “cutting off” (from the womb, referred to the cesarean section). This idea to be “cutted off” from darkness into light (and life) is an incredibly powerful image with a plenty of meanings.
Later Athena gave to Asclepius the power to exchange his blood with that of Medusa (note that the Gorgons originally have an apotropaic meaning), so that the blood spilled from his left-side would have been malicious and venomous, and the blood from his right-side miraculous and healer of all evil. He was considered able even to resurrect the dead, a hyperbole to describe his incredible talent, as reported by Diodorus Siculus (IV, 71.1): “he healed many sick whose lives had been despaired of, and for this reason it was believed that he had brought back to life many who had died”. For this ability to heal every illness and give a long life to mortals, Hades brought accusations against Asclepius, and fearing that he could delete the only true difference between the mankind and Gods (id est immortality), Zeus slew Asclepius with his thunderbolt – but he was soon forced to resurrect him as a minor deity (in the form of the constellation called Ophiuchus) in order to not arouse the anger of Apollo.
In Asclepius cult, the notion of healing is crucial to understand its Mysteries: healing is not simply a physical condition of health, but a condition that depends on the possibility to achieve a psycho-physical wellbeing through an experience of Gnostic matrix, lived on the thin wire that unite (and divide) Life and Death, Dream and Death.
It is evident that the body and the soul were considered a whole, because interdependent with one another, and able to influence one another. Then healing is not intended exclusively as the restoration of the health of the body, but also as a process to assure the health of the soul.
In the praxis for dream incubation, to understand how to treat the illness and heal, the wondered (the pilgrim) that aimed to receive an omen from Asclepius had to go to an Asclepeion and prepare to the experience through a period of purification, observing detailed behavioral, hygienic and alimentary norms, id est a diet in the strict sense, to cleanse the body and the soul from the waste. This process was intended as an actual catharsis, able to raise the mind and open it to the perception of the Divine. A particular required activity was the participation in the theatrical performances offered by the Asclepeion, because dramaturgy, thanks to the process of mimesis (that is the transposition of the performance on the performer) was considered able to induce an inner reflection. For this reason the patient was invited to compose poems, odes, chants and music, and even nowadays these activities are recognized as highly therapeutic.
After the period destined to purification and learning of the techniques from the priests, the pilgrim was in duty to make a donation to the temple, in money, prayers or others, because dream incubation was open to everyone, according to everyone’s possibility. It had to wait for Asclepius’ manifestation in dream to be called to the incubation. In that moment, the patient received a prayer, an actual spell, and the proper mysterical rite could begin. It consisted in sleeping in a sacred space, filled with incense fumes, on a floor covered by snakes, over the bloody skin of a goat flayed as a sacrifice. The role of the serpent is similar than in other traditions: basically, the it represent the possibility to change its skin and transform the inner Self, but also (medical) Knowledge and healing through the careful assumption of the pharmakon, the medicine, that is poison and remedy at the same time. Nevertheless, the word pharmakon designs also the scapegoat exiled during the ritual called Pharmakós, performed to bring purification over the polis. It is possible that the scapegoat was replaced by a slave or a criminal, and eventually sacrificed rather than exiled.
It is really important to underline that precluded to the devotees was not the rite of dreaming incubation itself, but the interpretation of the oracular dreams, that was open exclusively to the priestly caste of Asclepius. Many texts on this subject are survived, among them the Oneironautica of Artemidoros is meaningful because highlight the many difficulties for the incautious that expect to decipher the dreams without being able to distinguish their nature, in this way getting lost in a labyrinth of false symbols and false meaning, that don’t bring to healing, but to misfortune and madness.