Ase (also written ashe, and axe in Brazil) is, in Yoruba religious thought and the traditions descended from it, the power by which things come to be, the vital force or authority that makes an utterance effective and an action take hold. It is commonly glossed as "so be it" and used as an affirmation closing a prayer, but the affirmation depends on the concept beneath it: ase is what gives words the capacity to accomplish, so that saying it asserts that what has been spoken carries force.
Ase is understood to originate with Olodumare, the supreme being, and to be present in differing measures in the orisa, in human beings, in ancestors, in words, in certain plants, animals, minerals and objects, and in ritually prepared substances. It is not morally directional in itself, it is capacity rather than benevolence, and it can be accumulated, transmitted, concentrated and diminished. A very large part of ritual practice is concerned with the handling of ase: its transfer through initiation, its concentration in prepared objects and shrines, and its activation through the correct performance of praise poetry, drumming, dance and offering.
The concept underlies the Yoruba emphasis on the efficacy of speech. Oriki, praise poetry, and the verses of the Ifa corpus are not descriptions but interventions, and the babalawo's recitation is effective because of the ase carried by the words and by the diviner who speaks them. This is why accurate transmission matters so much in these traditions, and why improper or careless recitation is treated as a serious matter rather than an aesthetic failing.
Ase travelled with the transatlantic slave trade and remains central in Cuban Lucumi, in Brazilian Candomble, where axe also names the sacred foundation of a house of worship, so that a terreiro is spoken of as having axe, and across the wider Yoruba diaspora. Robert Farris Thompson's work brought the term to a broad art-historical readership from the 1980s, and it has since entered wider African-American and popular usage, at times detached from the ritual context that gives it its meaning. Practitioners have responded to that diffusion in varying ways, some welcoming the recognition and others regarding the casual use of the word as a loss.