As the existence of begotten things consists in perpetually acquiring (something or another), they will be annihilated by a removal of their future. An attribution of the future to the (intelligible) entities of a nature contrary (to begotten things), would degrade them from the rank of existences. Evidently they will not be consubstantial with existence, if this existence of theirs be in the future or past. The nature ("being") of begotten things on the contrary consists in going from the origin of their existence to the last limits of the time beyond which they will no longer exist; that is in what their future consists.[442] Abstraction of their future diminishes their life, and consequently their existence. That is also what will happen to the universe, in so far as it will exist; it aspires to being what it should be, without any interruption, because it derives existence from the continual production of fresh actualizations; for the same reason, it moves in a circle because it desires to possess intelligible nature ("being"). Such is the existence that we discover in begotten things, such is the cause that makes them ceaselessly aspire to existence in the future. The Beings that occupy the first rank and which are blessed, have no desire of the future, because they are already all that it lies in them to be, and because they possess all the life they are ever to possess. They have therefore nothing to seek, since there is no future for them; neither can they receive within themselves anything for which there might be a future. Thus the nature ("being") of intelligible existence is absolute, and entire, not only in its parts, but also in its totality, which reveals no fault, which lacks nothing, and to which nothing that in any way pertains to nonentity could be added; for intelligible existence must not only embrace in its totality and universality all beings, but it must also receive nothing that pertains to nonentity. It is this disposition and nature of intelligible existence that constitutes the aeon (or eternity); for (according to Aristotle)[443] this word is derived from "aei on," "being continually." DIFFERENCE BETWEEN ETERNITY AND PERPETUITY.