The Evangelical Universalist Forum

"Terms for Eternity: Aiônios & aïdios" talk part 1

The following was originally delivered as a talk, jointly by me and Ilaria Ramelli, in Edinburgh at the international conference of the Society of Biblical Literature, in 2006. A revised version appeared subsequently in the Mexican journal, Nova Tellus 24 (2006) 21-39. Please do let me know what you think of it.

Edinburgh-talk-Terms-for-Eternity.pdf (80.5 KB)

In the brief time we have today, we offer a summary of the research we are undertaking into the uses of two ancient Greek terms that are commonly translated as “eternal.” The terms are aiônios and aïdios. Neither word is to be found in the Homeric epics or in the major poems of Hesiod, although the noun aiôn, from which aiônios derives, is very common, mainly in the sense of a “life” or “lifetime.” Aïdios enters into Greek sooner, whereas aiônios first occurs, surprisingly enough, in Plato. Plato’s introduction of the term is philosophically significant, as is the fact that Aristotle eschewed it completely in his own copious writings. The subsequent history of these terms, and the dance in which they engage with each other throughout Greek literature and philosophy, is fascinating in itself, but the real pay-off is in the way they are employed in the Septuagint and the New Testament, and thereafter in Christian writers who are usually equally familiar with their connotations both in the pagan tradition and in Scripture. What is more, a great deal proves to be at stake in how these two terms are interpreted: in fact, nothing less than the prospect of the eternal damnation of sinners versus the universal salvation of all. Thus, what may seem to be a dry investigation of subtle terminological distinctions proves to be a key to understanding ancient philosophical and religious thought.

The notion of “eternity” is not simple, in part because “eternity” has multiple senses, in part too because some of these significances involve a high level of philosophical abstraction. On the one hand, terms for “eternal” may bear the loose sense of “a very long time,” as in the English “always,” without implying a rigorous notion of infinitely extended time. Even at this level, the Greek adverb aiei, like the English “always,” has at least two distinct connotations, referring both to an indefinitely prolonged stretch of time, equivalent to the English “forever” (“I will always love you”), and to an action that is regularly repeated (“he always comes late to class”). Again, there are intermediate uses, for example, “the house has always been on that street,” meaning that, as long as the house has existed, it has been in the same place, without any implication of unlimited duration. On the other hand, “eternal” may signify a strictly boundless extent of time, that is, greater than any numerical measure one can assign. This latter description is itself imprecise, of course. It may mean nothing more than “countless,” that is, too large to grasp, or grasp easily. But eternal time is more commonly understood to be strictly endless, with no termination at all. Even on this more rigorous conception, there are two senses in which time may be said to be eternal. It may have a beginning but no end; or it may have neither a beginning nor an end, but extend infinitely into the past and the future. What is more, in addition to all these varieties of “eternal,” the adjective has been appropriated also to denote something like “timelessness,” a changeless state that has no duration and hence is not subject to time at all.

To begin with aiônios in the presocratics, Ps.-Plutarch ascribes to Anaximander the idea that corruption and genesis occur in cycles “from an infinite aiôn,” but these are surely not Anaximander’s own words. Similarly, Hippolytus Ref. explains that Heraclitus “calls the eternal fire ‘Thunderbolt.’” Similar usages are ascribed to the Pythagoreans, but these again are clearly later inventions.

In contrast to aiônios, the adjective aïdios is attested in the sense of “eternal” or “perpetual” as early as the Homeric Hymn to Hestia and the Hesiodic Shield of Heracles, but in neither case does the expression does imply a technical sense of “eternal.” With the Presocratics, however, the term aïdios in the sense of “eternal” seems to come into its own, in a series of testimonies beginning with Anaximander and continuing on down to Melissus and beyond, although here again one must be careful to distinguish between paraphrases and original terminology. For Anaximander, any of the attributed sentences would, taken alone, be of doubtful authority; taken together, the several passages perhaps suggest that Anaximander himself may have applied the adjective aïdios to motion. For Xenophanes we have attestations of his use of aïdios in the sense not only of “indestructible” or “immortal” but also that of agenêtos, "uncreated. Again, the convergence of the various accounts suggests that Xenophanes may in fact have employed the adjective aïdios in reference to god or the universe. Two testimonies concerning Heraclitus cite aïdios as referring to the perpetual movement of things that are eternal and to the cyclical fire, which is god. Heraclitus’ use of the term aïdios in connection with cyclical phenomena is particularly noteworthy, for in later texts recurring or periodic events tend to be described rather by the word aiônios.

With Empedocles, we have the use of the term aïdios in his Katharmoi, guaranteed by the meter: “there is a thing of Necessity, an ancient decree of the gods, eternal.” Among the Eleatics, Parmenides is said to have described the “all” as aïdios, in that it is ungenerated and imperishable. As for Melissus, Simplicius provides what appears to be a direct quotation affirming that “nothing that has a beginning and end is either eternal [aïdion] or infinite.” It is worth noting that nowhere is the term aiônios ever attributed to the Eleatics. Finally, Democritus too argued that time was aïdios, on the grounds that it was ungenerated, and that the whole of things too was eternal (aïdion to pan).

It would appear, in sum, that the term of art for eternal things – all that is ungenerated and imperishable – among cosmological thinkers in the period prior to Plato was aïdios, never aiônios. In addition, aïdios is the standard adjective meaning “eternal” in non-philosophical discourse of the fifth century as well.

When we come to Plato, we find uses of both adjectives, aiônios and aïdios, in the sense of “eternal.” It is in the Timaeus that Plato enters most fully into the question of eternity, and here we find aïdios six times, aiôn four times, and aiônios twice. Plato introduces the concept in reference to the model that the demiurge followed in creating the sensible universe by looking “to the eternal” (pros to aïdion, bis). Then, in a crucial passage, Plato remarks that the created universe was seen to be moving and living, an image of the eternal gods (tôn aïdiôn theôn, 37C6), and adds that it was itself an “eternal living thing” (zoion aïdion). Plato goes on to say that it was the nature of the living thing to be aiônios but that this quality could not be attached to something that was begotten (gennêton). The creator therefore decided to make “a kind of moving image of eternity” (eikô d’epenoei kinêton tina aiônos), and so as he arranged the universe he made “an eternal image moving according to number of the eternity which remains in one” (menontos aiônos en heni kat’arithmon iousan aiônion eikona), and this he called “time.”

On the one hand, aïdios and aiônios appear to be virtually interchangeable: the model for the universe is “an eternal living thing” (zôion aïdion) and its nature is eternal (tou zôou phusis ousa aiônios). And yet, Plato seems to have found in the term aiôn a special designation for his notion of eternity as timeless; and with this new sense of aiôn, aiônios too seems to have come into its own as a signifier for what is beyond time. It was Plato who first articulated this idea of eternity, and he would appear to have created a terminology to give it expression. Plato’s conception of a timeless eternity remained specific to Platonism and closely related schools in antiquity.

Aristotle, as we have said, seems never to use the term aiônios, though there are nearly 300 instances of aïdios, which is Aristotle’s preferred word to designate things eternal. It is clear that Aristotle was not moved to adopt Plato’s novel terminology, whether because he perceived some difference between his own concept of eternity and that of his teacher, or because he felt that aiônios was an unnecessary addition to the philosophical vocabulary, given the respectability of aïdios as the appropriate technical term.

In the Stoics, aïdios occurs over thirty times in the sense of that which endures forever. It is applied to bodies and matter, the onta or realities that truly exist according to Stoic materialism, and above all to god or Zeus. To the extent that the Stoics employed aiônios and aiôn, however, there is either a connection with their specific view of cosmic cycles, as opposed to strictly infinite duration, or else the noun occurs in phrases indicating a long period of time. The Epicureans, in turn, regularly employ aïdios to designate the eternity of such imperishable constituents of the universe as atoms and void. Epicurus uses aiônios in reference to the future life that non-Epicureans expect, with its dreadful punishments: that is, to an afterlife in which Epicureans do not believe, and which does not deserve the name “eternal” (aïdios), properly reserved for truly perpetual elements.

Thanks heaps David. I will read through this over the next couple of days and give you some feedback :slight_smile:

Thanks for joining us David. Appreciate the contributions.

Alex (or David), is there an online article/essay that summarizes the book?


David, thank you for a great historical slice of the terms aionios & aidios. I might have no important comments until you get the part about the New Testament usage, but I’ll carefully read this series in the meantime.

Thanks for the link! I’m on it. Looking forward to it.


Very curious about the report myself!

I am not in any position to critique the paper so far, pro or con, but since he’s here and near the topic :mrgreen: : I do want to ask Dr. Konstan his opinion about the derivation of the term {aïdios}. It seems to be an evolved compound term, but would it be of a-idios (that which cannot be seen) or ai-dios (something to do with God/heaven/height)? Or a pun on both? Or does it have a traceable different derivation in the language than either of those? Perhaps back to Persian languages? (I strongly suspect this is true whether the term has one or some other prior meaning.)

Tom, this paper/talk was intended to summarise the book.

Jason, Aidios seems to derive from the adverb aei (or aiei), meaning “always”; but ancient Greeks themselves already punned on the possible sense of “invisible.” We discuss this briefly in the book.

Thank you, David. You definitely whet my appetite, especially for chapters 2, 3, and 4, the bulk of your book.:slight_smile:

I wonder, on the flip side of eternal punishment, Does your book address whether the New Testament clearly teaches that believers will live literally forever?

We argue that the New Testament seems to distinguish between the afterlife, which is eternal, and punishment in the afterlife, which may last for an eon but will end with the end of time. Eternal life is thus promised – not in this world, but the next. In what form? That’s a big question, which the church fathers considered carefully. We have some information on that, but there are other sources as well.

Excellent!–and such a pun (“always-god” “un-visible”) would be even more appropriate in context of Judaism (as thence into Judeo-Christianity.)

Ok I’d like to simplify all of this. Can anyone help?

  1. David said “It would appear, in sum, that the term of art for eternal things – all that is ungenerated and imperishable – among cosmological thinkers in the period prior to Plato was aïdios, never aiônios.”

Does this mean that we can say, before the time of Plato, the word “aionios” never appears in Greek writings to mean “without end.” Yes/No? Secondly, if “yes,” then how many writings/authors are we talking about approximately?

  1. Before Plato, “Aidios” did appear in Greek writings to mean “without end.” Yes/No? Secondly, if “yes,” then how many writings/authors are we talking about approximately?

  2. Plato was the first to use “aidios” in the sense of “without end.” Before him, we know of no authors who used it in this sense. Yes/No?

  3. Plato used aionios in the sense of “without end” but others used it in this sense before him. Yes/No?

  4. David said “Plato goes on to say that it was the nature of the living thing to be aiônios but that this quality could not be attached to something that was begotten (gennêton).”

So, in this context, does this mean that “aionios” also means “without beginning”?

  1. David said “Plato’s conception of a timeless eternity remained specific to Platonism and closely related schools in antiquity.”

So, again to confirm, does that mean that “timeless eternity” does not appear in any other Greek writings before his time? And, secondly, how many writings before his time do we know of that use this word?

  1. David said “Aristotle, as we have said, seems never to use the term aiônios, though there are nearly 300 instances of aïdios, which is Aristotle’s preferred word to designate things eternal.”

In his writings, does Aristotle consistently use the term “aidios” to mean “without end”?

Yes, aionios is not reliably attested before Plato.

Aidios appears in the sense of eternal before Plato in many presocratic writers.

Plato was NOT the first to use aidios in this sense; that’s how earlier philosophers use it.

Plato uses aionios in a special sense of “timeless.”

Plato uses aionios in a special sense of “timeless.”

Plato seems to have invented the idea of a timeless eternity.

Yes, Aristotle uses aidios precisely in this sense.

By the way, there is now a paperback and much less expensive edition of Terms for Eternity, with a couple of minor corrections as well. So we won that battle, although it’s still not quite as inexpensive as we’d like it.

All the best, David

David, thank you so much. So, if the idea of eternity “without end” appeared before Plato (in the form of aidios), then I am curious what contexts its appeared in such writings, and I am curious in particular if writers before Plato used that word to talk about the afterlife. If you have the time to respond to this, that would be great.

Secondly, how exhaustively do you list all Biblical references to “eternity” and “forever”? In your book, do you cite every verse that it appears?

Third, I see there is a paperback version of your book on Gorgias Press’ website. I intend to buy it for sure, but before I buy it from Gorgias, I want to know - do you also plan to make it available on I only ask for the practical reason that I have a gift card for Amazon and it would be nice to use it there. :slight_smile:

This is where Alex Smith referred me, and I’ll buy it here if you don’t plan to make it available on Amazon: … texts.aspx

P.S. Thank you so much! * Big smile *


Keep in mind that the few times {aidios} is used in the NT, could be construed as “invisible”, too or instead. David concurs that the pun is valid and was recognized (though the Greek philosophers didn’t primarily mean “invisible” by it); so if the NT contexts involve a relation of that which is seen to that which is unseen (where the latter is described by {aidios}), there would be strong grounds for inferring that the authors meant “invisible” (and maybe also “everlasting”, or maybe not, depending on further characteristics of the topic.)

I’ve discussed those contexts in-depth several times here on the forum, though I’ll have to look up where.

David’s second part of his talk can be found here, by the way. I think the notion of invisibility easily solves the problem of the term’s usage in Jude’s epistle.

I’m afraid I don’t know whether the book is available on Amazon, but one could request it and see what happens.

I can say that we do list all references to eternity in the Bible and elsewhere: the book is pretty exhaustive (and exhausting) that way.

As for Plato, he doesn’t speak of a timely eternity in connection with the afterlife, I think; after all, he thinks also of reincarnation, at least in some passages. He was really meditating on the nature of time. Think of the problem that Christian fathers raised, about whether the Son could be younger than the Father (as one would imagine) if the three Persons of God existed before the creation of time!

  I hope this is helpful,

  Very best, David

David, a big thank you to all your help and work. Since your book’s not on Amazon, I went ahead and ordered it from Gorgias Press just a minute ago. I can’t wait to get it in the mail!

Much respect and gratitude.

Jason - Does David address this kind of usage in his book? Or perhaps I need to ask David this (unless you know?)?

If you don’t know the answer, then can you tell me where you learned this? Where in Greek was the word aidios used to mean “invisible”? What documents, literature and contexts specifically?

I ran across it independently, but David confirmed earlier in this thread that the Greeks were aware of the pun and occasionally referred to it themselves. He says he and his co-author briefly discuss it in the book.

I should note that I’m probably wrong, in the comment linked above, about {aei} as “always” being a metaphorical application of a term that also entered our language as “high”–at least, etymologically that English word can be traced back to languages which are not Greco-Mesopotamian in origin, and it originally had a guttural ending (still represented by the now silent “gh” in modern spelling.) However, the origin of {aei} is highly disputed and I don’t think it’s coincidence that a slight variation of the term came to be used in Greek, as subsequently in English, as the word for “air”.

(I still think I’m right about {dios} being a variation of the term {deo}/{deva} from pre-Grecian languages, which is definitely about brightness, a different branch of the root term eventually becoming “day” by route of various terms meaning “hot” not “bright”.)

Jason Pratt - thank you!

I just got the book - Terms for Eternity - in the mail a few minutes ago! So excited!

Would anyone here like to join a Facebook discussion group (perhaps temporary) for the sake of discussing this book? I’m on there more often, that’s why I suggest it.

No need to buy the book: free at:- … _And_Philo %between% … to read this continuously click the rt-facing arrow, top right !!! Hope this is helpful Temple Farrar