# Eternity

An allegorical painting of a woman, representing eternity. She holds an hourglass, a skull rests on the table beside her, and an Ouroboros floats above her head. All of these are common symbols of eternity.

Eternity (or forever) is endless time. In philosophy and mathematics, an infinite duration is also called sempiternity, or everlasting. Eternity is an important concept in many religions, where the immortality of God (or the gods) is said to endure eternally. Some, such as Aristotle, would say the same about the natural cosmos in regard to both past and future eternal duration, and like the eternal Platonic Forms, immutability was considered essential.1

## Philosophy

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. Aristotle established a distinction between actual infinity and a potentially infinite count: a future span of time must be a potential infinity, because another element can always be added to a series that is inexhaustible.2 Aristotle likewise argued that the cosmos has no beginning. Euclid invoked this distinction instead of saying that there are an infinity of primes... rather that the primes outnumber those contained in any given collection thereof.3

## Symbolism

Eternity is often symbolized by the image of a snake swallowing its own tail, known as the Ouroboros (or Uroboros). The circle is also commonly used as a symbol for eternity, as is the mathematical symbol of infinity, $\infty$.