Eternity

Classical period (8th-7th century BC^[d] - 5th-9th century AD)^[e] Plato (c. 428–423 BC - 348/347 BC) described time as the moving image of eternity in Timaeus (37^[21] D^[22]) using the word: αἰών.^[23] Aristotle (384–322 BC) stated οὐρανοῦ was eternal (in Book I of Περὶ οὐρανοῦ)^[24][25] and an eternal world (in Physics). ^[26]

The ancient Greek word for everlastingness was ἀίδιος (aidios)^[27] as exists via Plotinus, who also used the word aoin ^[28] (eternity), in Ennead III.7. ^[29] The thought of Classical period Augustine, as exists in Book XI of the Confessions, and Boethius (c. 480–524 AD), in Book V of the Consolation of Philosophy were adopted as the reality of the subject for later thinkers in the western tradition of philosophy.^[30]

Thomas Hobbes (1588–1679) and many others in the Age of Enlightenment drew on the classical distinction to put forward metaphysical hypotheses such as "eternity is a permanent now".^[31]

Ancient Egyptian eternity terms were neheh, for cyclical time, and djet, for linear. ^{[32][33][34][35][36][37]} Rameses III ^[38] (c.1187-1156 B.C.E.) ^[39] funerary temple ^[38] was: 'United-with -Eternity' ^[40]

In Genesis 21:33 of the Old Testament ^[41] El-Olam ^[42] is God-Eternal. ^[41][42][43]

Mythic ^[44] Iliadical ^[45][46] ἀθάνατος (athanatos) is the immortal. ^[44]

Eternity as infinite duration is an important concept in many lives and religions. God or gods are often said to endure eternally, or exist for all time, forever, without beginning or end. Religious views of an afterlife may speak of it in terms of eternity or eternal life.^[f] Christian theologians may regard immutability, like the eternal Platonic forms, as essential to eternity.^[47][g]

The ancient greek word for everlasting and, or, eternal exists in the Orphica Hymni. ^[48]

Boethius stated eternity was: interminabilis vitae tota simul et perfecta possessio, ^[49] which is translated as "simultaneously full and perfect possession of interminable life".^[50][h] and nunc permanens, which in English is a: permanent now. ^[49] Thomas Aquinas (c. 1225 – 1274) believed in an eternal God, without either a beginning or end; the concept of eternity is of divine simplicity, thus incapable of being defined or fully understood by humankind.^[51]

The possibility of eternal universes with reference to General Relativity was a subject of physics since the 21st century. ^[52]

Eternity is often symbolized by the endless snake, swallowing its own tail, the ouroboros. The circle, band, or ring is also commonly used as a symbol for eternity, as is the mathematical symbol of infinity, ${\displaystyle \infty }$. Symbolically these are reminders that eternity has no beginning or end.