Seid (Old Norse: seiðr, sometimes anglicized as "seidhr", "seidh", "seidr", "seithr" or "seith") was a form of shamanism practised by pre-Christian Norse and arguably other Germanic cultures and continued in modern times by people who practice the reconstructionist beliefs of Ásatrú or heathenry. It involved the incantation of spells, which could amongst other things be termed galdrar or galðrar (sing. galdr or galðr, compare Old English: gealdor or galdor). Practitioners of seid were predominantly women (völva, or seiðkona, lit. seid woman). Although there were male practitioners (seiðmaðr, lit. seid man) as well, in the Viking Age, seid was considered ergi (perversity) for men, as its manipulative aspects ran counter to the male ideal of forthright, open behaviour.

The goddesses of Norse mythology were also practitioners of seid, along with Odin, a fact of which he was apparently ashamed, for the above mentioned reason. Anglo-Saxon people had words which appear to be cognate with seiðr: siden and sidsa, both of which are attested only in contexts which suggest that they were used by elves (ælfe); these seem likely to have meant something similar to seiðr (Hall 2004, pp. 117-30). Among the Old English words for practitioners of magic are wicca (m.) or wicce (f.), the etymons of Modern English witch, but no connection between wiccan and siden or sidsa is attested.

Forms of Seid

As described by Snorri Sturluson in his Ynglinga saga (sec. 7), seid includes both divination and manipulative magic. It seems likely that the type of divination practiced by seid was generally distinct, by dint of an altogether more metaphysical nature, from the day-to-day auguries performed by the seers (menn framsýnir, menn forspáir).

The Practice of Seid

In The Saga of Eric the Red, the seiðkona or völva in Greenland wore a blue cloak and a headpiece of black lamb trimmed with white cat skin; she carried the symbolic distaff (seiðstafr), which was often buried with her; and would sit on a high platform. In Örvar-Odd's Saga, however, the cloak is black, yet the seidkhona also carries the distaff (which allegedly has the power of causing forgetfulness in one who is tapped three times on the cheek by it). The colour of the cloak may be less significant than the fact that it was intended to signify the otherness of the seiðkona. How far the saga's elaborate description reflects pre-Conversion practice as opposed to the Christian author's imagination is, however, uncertain.

Our evidence suggests that during seances the seiðkona would enter a state of trance in which her soul was supposed to "become discorporeal", "take the likeness of an animal", "travel through space", etc. This state of trance may have been achieved through any of several methods: narcotics, sleep deprivation, sensory deprivation, etc. To galdra, i.e. the chanting of galdrar was also involved in the creation of the state of trance. The galdr and its Old English counterpart, the gealdor, has evolved into the word yell (modern Scandinavian: gala), and there are a number of kennings which compare the sound of battle to seid chanting. It is probable that this sound was very high pitched. That may be one reason why seiðr was regarded as unmanly.

Seid in Mythology

The goddess Freya is identified in Ynglinga saga as an adept of the mysteries of seid, and it is said that it was she who taught it to Odin: 'Dóttir Njarðar var Freyja. Hon var blótgyðja. Hon kenndi fyrst með Ásum seið, sem Vönum var títt' ('Njörðr’s daughter was Freyja. She was a sacrifice-goddess. It was she who acquainted first the Æsir with seiðr, which was customary among the Vanir').

In Lokasenna Loki accuses Odin of practicing seid, condemning it as an unmanly art. A justification for this may be found in the Ynglinga saga where Snorri opines that following the practice of seid, the practitioner was rendered weak and helpless.

One possible example of seid in Norse mythology is the prophetic vision given to Odin in the Völuspá by the völva, vala, or seeress after whom the poem is named. Her vision is not connected explicitly with seiðr, however: the word occurs in the poem in relation to a character called Heiðr (who is traditionally associated with Freyja but may be identical with the völva: see McKinnell 2001). The interrelationship between the völva in this account and the Norns, the fates of Norse lore, are strong and striking.

Another noted mythological practitioner of seiðr was the witch Groa, who attempted to assist Thor, and who is summoned from beyond the grave in the Svipdagsmál.