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 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.
[The post tomorrow shall consider the use of aiônios and aïdios in the LXX]
- Robin Parry
- Robin Parry is the husband of but one wife (Carol) and the father of the two most beautiful girls in the universe (Hannah and Jessica). He also has a lovely cat called Monty (who has only three legs). Living in the city of Worcester, UK, he works as an Editor for Wipf and Stock — a US-based theological publisher. Robin was a Sixth Form College teacher for 11 years and has worked in publishing since 2001 (2001–2010 for Paternoster and 2010– for W&S).