Etain had been hidden by the god Mider. The method used may have been that of drawing one of the rods by lot and then divining from the marks upon it. A similar method was used to discover the route to be taken by invaders, the result being supposed to depend on divine interposition.810 The knowledge of astronomy ascribed by Cæsar to the Druids was probably of a simple kind, and much mixed with astrology, and though it furnished the data for computing a simple calendar, its use was largely magical.811 Irish diviners forecast the time to build a house by the stars, and the date at which S. Columba's education should begin, was similarly discovered.812
The Imbas Forosnai, "illumination between the hands," was used by the Filé to discover hidden things. He chewed a piece of raw flesh and placed it as an offering to the images of the gods whom he desired to help him. If enlightenment did not come by the next day, he pronounced incantations on his palms, which he then placed on his cheeks before falling asleep. The revelation followed in a dream, or sometimes after awaking.813 Perhaps the animal whose flesh was eaten was a sacred one. Another method was that of the Teinm Laegha. The Filé made a verse and repeated it over some person or thing regarding which he sought information, or he placed his staff on the person's body and so obtained what he sought. The rite was also preceded by sacrifice; hence S. Patrick prohibited both it and the Imbas Forosnai.814 Another incantation, the Cétnad, was sung through the fist to discover the track of stolen cattle or of the thief. If this did not bring enlightenment, the Filé went to sleep and obtained the knowledge through a dream.815 Another Cétnad for obtaining information regarding length of life was addressed to the seven daughters of the sea. Perhaps the incantation was repeated mechanically until the seer fell into a kind of trance. Divination by dreams was also used by the continental Celts.816
Other methods resemble "trance-utterance." "A great obnubilation was conjured up for the bard so that he slept a heavy sleep, and things magic-begotten were shewn to him to enunciate," apparently in his sleep. This was called "illumination by rhymes," and a similar method was used in Wales. When consulted, the seer roared violently until he was beside himself, and out of his ravings the desired information was gathered. When aroused from this ecstatic condition, he had no remembrance of what he had uttered. Giraldus reports this, and thinks, with the modern spiritualist, that the utterance was caused by spirits.817 The resemblance to modern trance-utterance and to similar methods used by savages is remarkable, and psychological science sees in it the promptings of the subliminal self in sleep.
The taghairm of the Highlanders was a survival from pagan times. The seer was usually bound in a cow's hide—the animal, it may be conjectured, having been sacrificed in earlier times. He was left in a desolate place, and while he slept spirits were supposed to inspire his dreams.818 Clothing in the skin of a sacrificial animal, by which the person thus clothed is brought into contact with it and hence with the divinity to which it is offered, or with the divine animal itself where the victim is so regarded, is a widespread custom. Hence, in this Celtic usage, contact with divinity through the hide would be expected to produce enlightenment. For a like reason the Irish sacrificed a sheep for the recovery of the sick, and clothed the patient in its skin.819 Binding the limbs of the seer is also a widespread custom, perhaps to restrain his convulsions or to concentrate the psychic force.
Both among the continental and Irish Celts those who sought hidden knowledge slept on graves, hoping to be inspired by the spirits of the dead.820 Legend told how, the full version of the Táin having been lost, Murgan the Filé sang an incantation over the grave of Fergus mac Roig. A cloud hid him for three days, and during that time the dead man appeared and recited the saga to him.
In Ireland and the Highlands, divination by looking into the shoulder-blade of a sheep was used to discover future events or things happening at a distance, a survival from pagan times.821 The scholiast on Lucan describes the Druidic method of chewing acorns and then prophesying, just as, in Ireland, eating nuts from the sacred hazels round Connla's well gave inspiration.822 The "priestesses" of Sena and the "Druidesses" of the third century had the gift of prophecy, and it was also ascribed freely to the Filid, the Druids, and to Christian saints. Druids are said to have prophesied the coming of S. Patrick, and similar prophecies are put in the mouths of Fionn and others, just as Montezuma's priests foretold the coming of the Spaniards.823 The word used for such prophecies—baile, means "ecstasy," and it suggests that the prophet worked himself into a frenzy and then fell into a trance, in which he uttered his forecast. Prophecies were also made at the birth of a child, describing its future career.824 Careful attention was given to the utterances of Druidic prophets, e.g. Medb's warriors postponed their expedition for fifteen days, because the Druids told them they would not succeed if they set out sooner.825
Mythical personages or divinities are said in the Irish texts to have stood on one leg, with one arm extended, and one eye closed, when uttering prophecies or incantations, and this was doubtless an attitude used by the seer.826 A similar method is known elsewhere, and it may have been intended to produce greater force. From this attitude may have originated myths of beings with one arm, one leg, and one eye, like some Fomorians or the Fachan whose weird picture Campbell of Islay drew from verbal descriptions.827
Early Celtic saints occasionally describe lapses into heathenism in Ireland, not characterised by "idolatry," but by wizardry, dealing in charms, and fidlanna, perhaps a kind of divination with pieces of wood.828 But it is much more likely that these had never really been abandoned. They belong to the primitive element of religion and magic which people cling to long after they have given up "idolatry."
738. Cæsar, vi. 16.
739. Rh^ys, CB4 68.
740. Justin, xxvi. 2; Pomp. Mela, iii. 2.
741. Diod. Sic. xxii. 9.
742. See Jullian, 53.
743. Servius on Æneid, iii. 57.
744. Cæsar, vi. 16; Livy, xxxviii. 47; Diod. Sic. v. 32, xxxi. 13;