Orun

Yoruba cosmology is usually set out as a pair. Orun is the invisible half, Aye the visible, and the two are described in the Ifa corpus and in ordinary speech as halves of one thing rather than as two places. The image most often used is a closed calabash, its upper and lower shells fitted together with the world inside. Orun is not distant in the way a heaven above the sky is distant. It is the other side of a membrane crossed continually and in both directions. Olodumare, the supreme being, is in Orun and receives no cult of its own; the orisha, who do, are also there and are the beings actually addressed. The ancestors are there, and remain members of their lineages.

E. Bolaji Idowu's study of Olodumare in Yoruba belief set this arrangement out for a scholarly readership in the early 1960s and remains the reference point for it, including his argument that the Yoruba high being is genuinely supreme rather than a reading back of Christian monotheism, a claim that has been contested since. What follows from the pairing is that Yoruba religion has little use for the idea of leaving the world behind. A person's business is conducted in Aye, with the powers of Orun, on terms agreed before birth.

Movement between the halves is the practical content of Yoruba religion. Before birth a person kneels before Olodumare and receives ori, the destiny or inner head, which is carried into Aye and can be improved or spoiled but not exchanged. At death the person returns, and if the life was well made is received among the ancestors, who may be reborn into the same lineage; egungun masquerade brings them back into the town in visible form for a season. In between, the orisha are the parties one deals with, each with its own devotees, foods, prohibitions and shrines. The road across is not open to anyone at will, which is why divination exists.

Ifa, presided over by Orunmila, is the system by which a diviner casts and reads figures to learn what Orun has to say about a matter in Aye, and Eshu is the one who carries the offering and the message, which is why he is served first. The atlas records Orun in the Heavens grouping because it is the abode of the supreme being and of the honoured dead, and notes that the fit is inexact: Orun is a cosmological half rather than a reward, and the sources describing orun rere and orun buruku are describing reception by the ancestors more than a sentence passed on a soul.