from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The midpoint between time and eternity; the mode of being of the angels, saints, and celestial bodies (which mediaeval astronomy believed to be unchanging)
Therefore, these are measured by aeviternity, which is a mean between eternity and time.
Since Sacred Scripture reveals that both heaven and earth did have a beginning, neither corporeal nor spiritual creatures are eternal; but the different ways in which they are subject to change differentiates the time in which corporeal things exist from the aeviternity of the angels.
A moment later, if one can speak of anything like temporal succession in aeviternity, some are no longer there.
To name the middle ground between (a) time, in which all corporeal creatures have their mutable existence, and (b) eternity, in which God exists immutably without beginning or end, the theologian calls it (c) aeviternity.