“The days followed one another patiently. Right back at the beginning of the multiverse they had tried all passing at the same time, and it hadn’t worked” – Terry Pratchett

Your universe amuses us...
Your universe amuses us…

If Hugh Everett’s relatively mainstream “Many Worlds Interpretation” of quantum mechanics has any merit, that is, that our inability to absolutely predict certain observations results from the fact that for every observation there are a range of possibilities, each with a different probability, and each probability corresponds to a different universe, the layman’s version of such a probabilistic monstrosity is that with every decision we make, a parallel universe forks off where we made a different decision.  Given my general lack of judgment, this suggests that there are a whole lot of universes out there that are pretty screwy.  Don’t worry, that’s just me.  Your many universes are wonderful.  Filled with rainbows, inhabited by friendly unicorns, and smelling of roses.  I’m nonetheless warmed by the thought that there is a universe out there where I’m a handsome and talented rock star.  Perhaps the probabilities are a little too low on that one, given my decision trees.  At any rate, ever since we started getting all hot and bothered about quantum mechanics, physicists have been speculating about the existence of multiple or parallel universes, and patting themselves on the back for their theoretical wackiness.  As it turns out, a few savvy Classical philosophers, acutely aware that reality was not always what it seemed, came to the same conclusion without the help of supercolliders and brain-bending mathematics.  They merely looked around and observed that we live in a messed up universe, where inexplicable phenomena routinely occur and strange creatures slip in and out for a visit, as if our physical laws just didn’t apply to them.  It’s not that you shouldn’t hug the nearest quantum physicist and declare, “Look at the big brains on Brad”, rather as you’re giving them a little love squeeze, whisper in their ears that the classical Greeks and Romans kind of already figured out that we live in a multiverse.  You never know what turns people on.

Anaximander (610-546 B.C.) was a Greek pre-Socratic philosopher kicking it old school in Ionia (modern Turkey) getting tutored by Thales (who many, including Aristotle regarded as the first philosopher of the Greek Tradition) and rapping snot-nosed Pythagoras on the knuckles for talking too much in class.  Anaximander wasn’t much inclined to attribute the mechanics of the universe to those hard-partying Greek gods, which largely differentiated him from the philosopher-scientists that preceded him.  Unfortunately, temporal fame is eventually trumped by entropy, so all but one fragment of Anaximander’s works have been lost to history, and what we have ended up with are little citations here and there by other scholars writing hundreds of years later.  The Byzantine philosopher Simplicius (490-560 A.D.) was a pretty prolific writer and researcher, and if not for him, much that we know about pre-Socratic philosophy might have been obliterated by the sands of time.  Luckily, he was a big fan of Anaximander, thus we know that Anaximander elaborated an ingenious theory of the multiverse, hinting at a belief that there are innumerable co-existent realities, a reading of which is frequently debated given that we have almost nothing written by Anaximader himself, and relying heavily on his explicit use of plurals.

Of those who claim that the ‘principle’ is one, in motion and ‘unlimited’, Anaximander, son of Praxiades, a Milesian who became the successor and student of Thales, said that ‘the unlimited’ is the principle and ‘element’ of the things that exist, and he was the first to introduce this name for the principle. He says that it is neither water nor any of the other so-called ‘elements’, but some other nature which is ‘unlimited’.  Out of this come to be all the heavens and the worlds in them. And the sources from which all the things that exist have come to be, are also the ones into which these (things) get destroyed, in accordance with what must be. For they give justice and reparation to one another for their injustice in accordance with the ordinance of time, as he says in a rather poetic fashion. It is also clear that, having observed the change of the four elements into one another, he did not think fit to make one of these an underlying element, but something else apart from these (Simplicius, 24.13-23).

There must be something in the water in Ionia, as another Ionian philosopher named Leucippus (5th Century B.C.), generally credited with being one of the first Greek thinkers to develop the theory of atomism (everything in the universe composed of some sort of indivisible element, atoms that is), was big on the metaphysics of multiple worlds.  Again, we only have fragments and vague references to him, mostly concerned with the fact that he was the teacher of the more famous Democritus (470-360 B.C.), and some scholars deny he even existed.

Whether or not Leucippus, as the pioneer of atomism, was influenced by the views of the Eleatics, he agreed with Parmenides concerning the impossibility of the genesis and decay of the world, and hence regarded Being as original, homogeneous. But to account for Becoming, Leucippus held that Being moves; it consists of innumerable, ever-living elements or atoms, each compact and full, incapable of being divided, moving in the empty space between. The atoms are assumed to account not only for all change but the multiplicity, variety, and form of all organized things, all differences in nature being quantitative, due to various arrangements of atoms which are all qualitatively the same. The atom as conceived by Leucippus and Democritus is not then an idealistic Number, not a mere point; it has magnitude, and is physically indivisible, not mathematically so. The atoms have both extension and weight; since they differ in shape, position, and arrangement, various combinations are possible, and visible things are aggregates of invisible atoms. Innumerable worlds are possible as results of the original “mighty void,” which may have been a single vortex or whirl (Dresser, 1926, p63-64).

Heady stuff for a non-existent philosopher, if you ask me.  The idea is that many universes can result from “abscission from the infinite”.  Democritus picked up where Leucippus left off, tellingly noting the absence of certain standard elements of our universe in other worlds, suggesting he wasn’t simply suggesting the existence of other planets, rather of parallel realities where our rules did not necessarily apply.

Democritus holds the same view as Leucippus about the elements, full and void…he spoke as if the things that are were in constant motion in the void, and there are innumerable worlds, which differ in size. In some worlds there is no sun and moon, in others they are larger than in our world, and in others more numerous. The intervals between the worlds are unequal, in some parts there are more worlds, in others fewer, some are increasing, some at their height, some decreasing, in some parts they are arising, in others failing. They are destroyed by collision one with another. There are some worlds devoid of living creatures or plants or any moisture (Hippolytus: I, 13, 2).

Epicurus (341-270 B.C.), certainly better known to us for his emphasis on “pleasure” as the greatest good, also subscribed to a many worlds interpretation in his cosmological speculations.  In particular, Epicurus added the notion that the infinity of worlds could be adjacent or wholly contained inside each other in the sense that one might occasionally overlap another, remarkably close to our modern ideas of parallel universes.

‘We see that the number of such worlds is infinite, and that such a world may arise either within another world, or in the intermedial spaces, by which we mean the intervals of empty space between different worlds.’ As we have seen, Epicurus maintained that any number of divergent explanations of the formation of the things composing a world might be equally good, provided that they only exclude all divine agency and conform to the general principles of atomism (Taylor, p69).

Plato and Aristotle hated these pre-Socratic atomists with a passion (it was recorded by Aristoxenus of Tarentum in the 4th Century B.C. that Plato wished all of Democritus’ books could be burned), as a central feature of both their respective philosophies was that our reality was unique, and that no other system of worlds or strange sort of cosmic pluralism could possibly exist.  Given the popularity of Plato and Aristotle in the later formation of Western theology and philosophy, the fact that they had better publishing contracts, and the correspondence of the Platonic/Aristotelian ideas with those of the up and coming Christian church, for a about a millennia, the notion of a plurality of worlds fell out of favor, and nobody talked about it much.  Sadly, we were left without a potential explanation for all the bizarre things that kept popping up in our reality for a few thousand years, apart from the notion that our singular divinity “moves in mysterious ways”.   No doubt, we like to think we are unique and special, hence the appeal of singular conceptions of our existence, or as astronomer and Director of SETI, Seth Shostak phrased it, “The next time you check your moves in the mirror and reflect on how special you are, consider that somewhere in this universe or in another parallel universe, your double might be doing the same. This would be the ultimate Copernican Revolution. Not only are we not special, we could be infinitely ordinary”.

Dresser, Horatio W. b. 1866. A History of Ancient and Medieval Philosophy. New York: Thomas Y. Crowell, 1926.
Kirk G. S., Raven J. E. and Schofield, M. The Presocratic Philosophers: A Critical History with a selection of Texts, 2nd edition, Cambridge University Press, 1983.
Simplicius, Commentary on Aristotle’s Physics.
Taylor, A. E. 1869-1945. Epicurus. New York: Dodge, 1910.