Aion, Khronos.

Whereas khronos – as represented by Kronos, the god who devours his own children – presents us with all the characteristics of ‘time', aiôn, by way of contrast, is a term for which there is no modern equivalent. In Homeric poetry, aiôn designates the vital fluid, and hence a man's lifespan and destiny, the intensity of a portion of time. But when Plato, in the Timaeus, relates aiôn to divine life rather than to a human portion, we encounter ‘eternity' in the sense which Aristotle will also retain for his first ‘unmoved mover', and which Plotinus will construe as the way in which Being exists. Khronos becomes the ‘moving image' of aiôn, and in the Neoplatonist readings, its ‘son'. Thus, the Greek opposition between aiôn and khronos does not coincide with any of those with which we are familiar. Transliterated into aevum, aiôn was adopted and adapted for the purposes of Christian theology. For Aquinas, ‘strictly speaking, aevum and aeternitas are no more distinct than are anthropos and homo'. However, in the course of the 13th Century, aevum detached itself from aeternitas and began to designate something intermediate between time and eternity. Ockham redefined this unstable intermediate position in terms of a common, homogeneous time, which provided the foundation for the functional-objective representation of time in the Classical age (Descartes). In the development of speculative philosophies of history in the wake of Kant, the notions of aiôn and aevum were put to work again, in an entirely different doctrinal context. The Schellingian Ewigkeit rediscovered the vitalism of the aiôn, which in turn informed the Bergsonian experience of duration.