W.B. Yeats published 'A Vision' in 1925, outlining a complex system of historical cycles, lunar phases, and psychological types that he claimed were dictated by spiritual entities. This work reflects Yeats's deep interest in mysticism and the occult, blending poetry with philosophical inquiry. 'A Vision' has been influential in both literary and esoteric circles, offering insights into the nature of time, existence, and the human psyche.

W.B. Yeats' 'A Vision,' published in 1925, provided a complex symbolic framework that underpinned many of his later poems. This self-invented mythology allowed Yeats to explore profound themes of existence, spirituality, and the cyclical nature of life, enriching the modern poetic canon.