Eternity (or forever) is endless time. It is often referenced in the context of religion , in the concept of immortality , whereby death is conquered, and people may live for an unlimited amount of time (cf. Heaven ). The existence of gods or God is said to endure eternally and sometimes also the natural cosmos, in respect to both past and future.

By contrast, the concept of a mathematically infinite duration, is called sempiternity or everlasting. Whereas the eternal is said to be unchanging and outside time; a potentially sempiternal span of time can never come to pass in actuality.^[1] Aristotle argued that cosmos has no beginning.

The idea of eternity

The metaphysics of eternity studies that which necessarily exists "outside" or independently of space and time . Another important question is whether "information" or Form is separable from mind and matter .

God and eternity

Theists say that God is eternally existent. How this is understood depends on which definition of eternity is used. On one hand, God may exist in eternity, a timeless existence where categories of past, present, and future just do not apply. On the other hand, God will exist for or through eternity, or at all times, having already existed for an infinite amount of time and continuing to exist for an infinite amount of time. One other definition states that God exists outside the human concept of time, but also inside of time. The reasoning for this definition is that if God did not exist both outside time and inside time, God would not be able to interact with humans.

Aristotle established a distinction between actual infinity and a potentially infinite count, for example, instead of saying that there are an infinity of primes, Euclid prefers instead to say that there are more prime numbers than contained in any given collection of prime numbers.^[2] According to Aristotle, a future span of time must be a potential infinity, because another element can always be added to a series that is inexhaustible: "For generally the infinite has this mode of existence: one thing is always being taken after another, and each thing that is taken is always finite, but always different".^[3]

Augustine of Hippo wrote that time exists only within the created universe, so that God exists outside time:

In the eminence of thy ever-present eternity, thou precedest all times past, and extendest beyond all future times, for they are still to come — and when they have come, they will be past. But "Thou art always the Selfsame and thy years shall have no end." Thy years neither go nor come; but ours both go and come in order that all separate moments may come to pass. All thy years stand together as one, since they are abiding. Nor do thy years past exclude the years to come because thy years do not pass away. All these years of ours shall be with thee, when all of them shall have ceased to be. Thy years are but a day, and thy day is not recurrent, but always today. Thy "today" yields not to tomorrow and does not follow yesterday. Thy "today" is eternity.^[4]

—St. Augustine, Confessions, Book XI, Chapter XIII

See all the biblical passage 2Pe:3:8: “But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day.”

Symbolism

Eternity is often symbolized by the image of a snake swallowing its own tail, known as Ouroboros (or Uroboros), though the symbol can also carry a number of other connotations.

The circle is also commonly used as a symbol for eternity. The related concept, infinity , is symbolized by , which may be based on the Ouroboros.

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  The Ouroboros .