The Great Conversation: Eternity
By Gabriel Blanchard
"Forever" is a word we use lightly, but it has great philosophical heft.
During quarantine, ideas like eternity and time dilation can go from “abstract speculation” to “oh, I could have told you that.” Eternity can therefore be a very useful point of entry into the great conversation, in which it has (appropriately) been a perennial topic.
The first, obvious meaning of eternity is endless duration. In one sense, this is unimaginable: our experiences always have a beginning and an end. On the other hand, even when we think about the beginning or end of the universe, we always seem to find ourselves wondering about “before” the beginning” or “after” the end. Time just stopping doesn’t seem any more congenial to our minds than its going on forever; this helps illustrate the distinction between being able to imaginatively picture something and being able to grasp it as an idea, a distinction that comes in handy in a lot of other contexts (in math, for instance, it’s easy to understand the difference between the numbers three and a million, yet next to impossible to picture it).
Thinking about eternity often has a “practical” side, especially in religious contexts. Many religions consider the soul eternal in one or more senses, which raises the question of its fate after death. Indic religions like Hinduism and Buddhism tend to believe in reincarnation; many traditions treat the soul as simply going on without a body forever, whether in a negative, deprived sense (as in many forms of paganism) or in some exalted state (as in Gnosticism). The Abrahamic faiths mostly assert a final, miraculous reunion of the soul with its original body, in combination with a cataclysmic final judgment and radical re-ordering of the world—resurrection to heaven or hell.
But eternity has also been interpreted differently, as being a different kind of time from what we experience, or as being outside time altogether, as a three-dimensional space is “outside” a one-dimensional line. Though older than Christianity, this notion of eternity was taken up by Christian theologians like St. Augustine and St. Thomas Aquinas as a way of understanding the mind of God. In particular, it has been applied to the problem of providence: how God’s foreknowledge can coexist with human free will. Boethius, a fifth-century Roman, used a time-transcending idea of eternity to explain providence, essentially describing the “fore-” part of “foreknowledge” as a kind of misnomer; to God, whose being is infinite, all times are present, and so he does not foresee but simply sees. His surprisingly concise book The Consolation of Philosophy was an international favorite for over a millennium, and was translated into English by Alfred the Great, Chaucer, and Queen Elizabeth.
Einstein’s theories of relativity dealt with time proper, rather than eternity, but some of their implications have bent back toward the question of whether eternity exists, and in what sense. The inconsistency between Einstein’s picture of the universe, and that offered by quantum physicists like Bohr, Planck, and Heisenberg, has prompted some physicists to search for a “unified field theory” that fits both. This in turn has led to speculations like string theory, some versions of which posit many more dimensions, of time as well as space, than we can directly perceive—a possibility that is, at the least, very like eternity.
Plotinus, The Enneads (Ennead III, Tractate 7)
Boethius, The Consolation of Philosophy
Brian Greene, The Elegant Universe
Image overlay: The Persistence of Memory, Salvador Dalí, 1931