Twins are treated relatively kindly in modern fantasy, but it was not always so. In almost every traditional society, Taboo enshrouds the birth of twins, and the fate which may be meted out to them (and their mothers). Twins evoke a sense of the sacred in peoples who lack a biological science which can assure them that simultaneous double births are natural: for good or for ill, twins are likely to be caused by the gods.
Unsurprisingly, the twin gods who feature in numerous Pantheons tend to manifest a variety of aspects, not all of them easy to contemplate linked together. But there may be an underlying pattern, which may be described as communication, or passage (> Recognition). Twin gods preside over Rituals of Fertility; they found cities; they help (but also threaten) humanity with advice; they protect those who travel (but those who travel leave their homes, undertake great risks, and may cause change upon their return). Among the better-known twin gods are the Egyptian Osiris and Set, the Hindu Yama and Yami – whose incest is followed by their becoming rulers of the Underworld, a place where at least one twin may often expect to be enthroned or immured – the Hindu charioteers called the Asvins, the similar Greek charioteers Castor and Polydeuces, and their Roman equivalents, Castor and Pollux.
In myth and Religion and Legend, twins like Eve and Lilith, Esau and Jacob, Jesus and Thomas called Didymus, Zethus and Amphion, and Romulus and Remus are frequently distinguished from one another by the fact that one is human, the other supernatural. In this fashion, their compact is a form of communication between this world and another (> As Above, So Below).
Examples of fantasies that have much to say about twins include: Charlotte Brontë's The Spell (1931 chap); Alexandre Dumas's The Corsican Brothers (1844), in which Siamese twins are psychically linked, at a distance, and through extraordinary ordeals; David H Keller's The Homunculus (1949), in which Pan and Lilith are emblematical twins; H Burgess Drake's Hush-A-Bye Baby (1952), in which unborn twins haunt their mother; Thomas Tryon's The Other (1971); many of the works of Vladimir Nabokov, either explicitly or hidden within the text, but most specifically Ada, or Ardor: A Family Chronicle (1969); John DeChancie's Castle Perilous sequence, in which the legitimate ruler of the central Edifice and the Dark Lord who opposes him are twins; much of Steve Erickson's fiction; Raymond E Feist's Faerie Tale (1988), in which one twin is replaced by an ominous Changeling; Tamora Pierce's Lioness Rampant (1988), in which twinning and Gender Disguise intertwine; Elizabeth Hand's Winterlong (1990), where twins circle one another in moves that deliberately echo William Shakespeare's Twelfth Night (performed circa 1602; 1623); Victor Kelleher's Brother Night (1990 UK); Morgan Llywelyn and Michael Scott's Silverhand: The Arcana (1995); and Tim Powers's Expiration Date (1995). Movies and tv find the visual opportunities of twinning particularly compelling: examples include Bewitched (1945), I Dream of Jeannie (1965-1970), Oh God! You Devil (1984) – where God and Satan are both played by George Burns – and The Dark Half (1991). [JC]