Yggdrassil of Germanic legend is the tree on which Odin, the Germanic god of magick, hung himself in order to win the runes from the deep dark cthonic underworld. Yggdrassil represents the axis of the world, connecting the underworlds in its deep and dark roots all the way up the trunk to the brightest spiritual realms in the uppermost branches. This symbolic structure could be used to transport the consciousness into different spirit worlds (dimensions) through the practice of astral projection or the inducement of astral visions in the Mind's Eye.
Accounts of both astral projection and prophetic dreams abound in Germanic legends. Through this talent a witch or sorcerer could sometimes gain information of goings on in the earthly plane, as well as contacting the worlds of the spirits. In one Germanic saga a witch named Thordis relates that: "I took a witch's ride to many places this night, and I learned with certainty things I did not know before."
Odin himself is described astral projecting in the the Ynglinga Saga, in which we read that: "Odin could transform his shape: his body would lie as if dead, or asleep; but then he would be in shape of a fish, or worm, or bird, or beast, and be off in a twinkling to distant lands upon his own or other people's business."
The Laplanders were also renowned for their ability to astral project, and were famed for their shamanic talents. Many accounts exist of Laplanders who would travel to a distant location and then relay accurate information. While astral projecting the Laplanders would also physically isolate themselves, during which time they believed it was dangerous for anyone to touch their inert physical bodies.
Astral Visions and Prophetic Dreams
Astral visions and dreams often overlap. The difference between a dream and projection is mainly the degree to which conscious awareness that is maintained without terminating the deep trance state necessary to sustain the oneiric landscape. Witches practicing the craft of seidr were known to enter a deep trance state close to sleep in which astral visions would be received, or through which they could communicate with spirits. Often a warrior in a saga would fall into a restless sleep and thrash around, after which they would relate a prophetic dream involving an attack by wolves or other beasts, predicting an impending battle with enemy warriors.
In the Germanic tradition the wolves or other beasts were not merely symbolic dream metaphors, but were often the personal guardian spirits of the warriors— known as the Norse fylgja or Anglo-Saxon Fetch. In The Saga of Havard of the Ice Fjord, Thorgrim — a sorceror riding with a pack of eighteen warriors to kill Havard at Otradal — is overcome with sleepiness and dismounts. He lies down with a coat spread over his head (sensory deprivation facilitates the astral vision) and falls into a restless "sleep," in which state he projects to Otradal. At the same time, however, the warriors at Otradal are kept awake by the restlessness of one of their own company, who is projecting and viewing the approach of Thorgrim and the enemy warriors in animal form. They wake him and he says: "...I saw some wolves coming from the South, running through the field, eighteen in all, with a female fox running in front of them. I have never seen such a tricky beast as she was. She was looking all around . . . I know with asbolute certainty that these were human spirits." Thorgrim's "astral body" appearing as a female fox probably indicates that it was his gender-opposite Fylgja (Fetch) that was seen by the entranced warrior.
Dangers of the Spirit Worlds
The descent to the underworld was often considered dangerous, as the spirits of the cthonic realms may be reluctant to allow a shaman to win knowledge or powers from the underworld and return with them alive. Germanic lore also contains many accounts of the phenomenon of "repercussion," in which wounds sustained by an the astral body of a sorcerer or witch manifest on their physical bodies, sometimes fatally.
Odin was said to have the power to aid his allies and fight battles by astrally possessing (or shape-shifting into) a huge bear— but any wounds sustained on the body of the beast would then appear on his own inert physical body. Another account in the sagas describes some seidr-women who entered a state of deep trance while their physical bodies lay inert on a raised platform (seiðhjallr). They projected out of their bodies travelled on the back of a monstrous whale to attack enemies on board a ship to prevent them from reaching land. The company on board the ship fought back, however, and the death blows dealt to the projected doubles broke the physical backs of the witches, who toppled dead from the high platform.
In a non-combative context, the Chronicon Norvegiae related the story of a shaman who entered a deep trance to seek out the soul of a woman who had suddenly died. A dreadful wound suddenly appeared on the shaman's body during this work, killing him. Later another shaman managed to revive the woman, who said she had seen the spirit of the first shaman swimming in the form of a walrus when someone struck the beast with a weapon.
This phenomenon, known as "repercussion," is not as implausible as it might sound. The same faculties of the subconscious mind which enable astral travel also have the power to cause (or cure) physical injuries. In a positive context this is how healing suggestions under deep hypnosis can cause miraculous cures— but in the negative context subjects placed in a state trance can manifest tangible physical injuries in response to suggestion. Many hypnotists have demonstrated this by telling a subject that the tip of a pencil is a lit cigarette, resulting in the appearance can actually cause physical blisters to appear on the skin. The same faculties are also the mechanism (if not the cause) that enables the phenomenon of stigmata, in which real physical wounds appear on the hands of devout believers in the crucifixion.