Episode 116 - Letter to Herodotus 5 - More Fundamentals of Physics
Date: 04/08/22
Link: https://www.epicureanfriends.com/thread/2448-episode-one-hundred-sixteen-letter-to-herodotus-05-more-fundamental-physics/
Summary
Section titled “Summary”Episode 116 continues the panel’s review of Epicurus’ Letter to Herodotus, covering sections 41–45 on fundamental physics. Joshua draws a direct connection between Epicurean atomism and the rejection of a “first cause”: because Epicurus affirms an infinite regress of causation extending back through eternity, the indivisibility of atoms is the necessary stable mechanism for that eternal chain — the same logical stance that directly undermines Thomas Aquinas’ Five Proofs for the existence of God. The group reflects on George Santayana’s judgment that atomism is “the greatest idea that mankind has ever hit upon,” and Joshua traces its persistent challenge to religious authority through John Tyndall’s controversial 1874 Belfast Address. Martin explains how atomism provides mechanistic explanatory power that continuum theories in physics cannot match, and the panel examines translation discrepancies in Bailey’s edition — including whether atoms “fall straight down” or travel on a “perpendicular path” — alongside a broader discussion of ancient scriptio continua manuscripts, illustrated by the memorable story of Timothy Dexter’s punctuation-free memoir.
Transcript
Section titled “Transcript”Cassius:
Welcome to episode 116 of Lucretius Today. This is the podcast dedicated to the poet Lucretius, who wrote On the Nature of Things, the only complete presentation of Epicurean philosophy left to us from the ancient world. I’m your host Cassius, and together with our panelists from the EpicureanFriends.com forum, we’ll walk you through the ancient Epicurean text and discuss how Epicurean philosophy can apply to you today. We encourage you to study Epicurus for yourself, and we suggest the best place to start is the book Epicurus and His Philosophy by Canadian professor Norman DeWitt. If you find the Epicurean worldview attractive, we invite you to join us in the study of Epicurus at EpicureanFriends.com, where you’ll find a discussion thread for each of our podcast episodes and many other topics. Today we continue our review of Epicurus’ Letter to Herodotus and move further into fundamental physics. Now let’s join Joshua reading today’s text.
Joshua:
“And these latter are indivisible and unalterable — if, that is, all things are not to be destroyed into the non-existent, but something permanent is to remain behind at the dissolution of compounds. They are completely solid in nature and can by no means be dissolved in any part. So it must needs be that first beginnings are indivisible corporeal existences.
“Moreover, the universe is boundless, for that which is bounded has an extreme point, and the extreme point is seen against something else, so that as it has no extreme point it has no limit, and as it has no limit it must be boundless and not bounded.
“Furthermore, the infinite is boundless both in the number of the bodies and in the extent of the void; for if on the one hand the void were boundless and the bodies limited in number, the bodies could not stay anywhere, but would be carried about and scattered through the infinite void, not having other bodies to support them and keep them in place by means of collisions. But if on the other hand the void were limited, the infinite bodies would not have room wherein to take their place.
“Besides this, the indivisible and solid bodies, out of which too the compounds are created and into which they are dissolved, have an incomprehensible number of varieties in shape; for it is not possible that such great varieties of things should arise from the same atomic shapes if they are limited in number. And so, in each shape, the atoms are quite infinite in number, but their differences of shape are not quite infinite, but only incomprehensible in number.
“And the atoms move continuously for all time, some of them falling straight down, others swerving, and others recoiling from their collisions; and of the latter, some are borne on, separating to a long distance from one another, while others again recoil and recoil, whenever they chance to be checked by the interlacing with others, or else shut in by atoms interlaced around them. For on the one hand the nature of the void which separates each atom by itself brings this about, as it is not able to afford resistance, and on the other hand the hardness which belongs to the atoms makes them recoil after collision to as great a distance as the interlacing permits separation after the collision. And these motions have no beginning, since the atoms and the void are the cause.
“These brief sayings, if all these points are borne in mind, afford a sufficient outline for our understanding of the nature of existing things.”
Cassius:
Joshua, thank you for reading that for us this morning. We’ve now been reading this for several weeks and gone through only a short portion of each section at a time. Today we’re probably going to speed up and cover all the way from 41 through 45. The material here today strikes me as some very strict atomism basics, with some of the same epistemological points raised earlier in the abstract. Those epistemological points are still here — we can go through each of these paragraphs and make observations about the method of reasoning involved, and that is probably one of the things I’d most like us to do: continue to talk about the method of reasoning, and also talk about how Epicurus was structuring a system he thought would be understandable. This is a summary written to Herodotus — a system that would allow people to have, as he said at the end, “a sufficient outline for our understanding of the nature of existing things.” In other words, a general worldview that would be in competition with, and replace, the supernatural worldview in which we could get struck by lightning by a mad god at any moment.
It’s certainly not something we today would consider grounds for competing with current physics. But we can observe many parallels and insights that have proven to some extent to be true. There are also aspects that we put in an entirely different framework — of energy, fields, or other ways of looking at things that don’t fit into the old hard-body model, as Martin has talked about in the past.
We’ve already been through this once in the Lucretius podcast, maybe even two years ago now. If someone is interested in the physical aspects and the detailed argument of each point, they can find more information in the corresponding section of Lucretius. But for our purposes — going through the Letter to Herodotus and talking about an outline of the entire system that relatively non-professional people can use to understand how to live day-to-day life — it’s probably better to approach it at a higher level.
The points here, if we were just listing them, are mostly included in that list of twelve fundamentals that several different people have compiled over the decades. So apparently Epicurus did think it was useful for people to remember certain basic points in general — that the universe is boundless in the number of bodies and extent of void, that atoms are moving continuously, some falling straight down, others not. With that as background, let’s go through these paragraphs and pick out what we think is the most important takeaway still important for a modern person to think about. If we go back to section 41, he’s starting by referring to solid bodies as indivisible and unalterable, so that the first beginnings are indivisible corporeal existences. Who would like to pick that out and comment? Is this the issue of infinite divisibility? Most people today aren’t thinking about infinite divisibility at any given moment, but apparently at that time it was a big issue between the philosophers. Who wants to take up infinite divisibility and why Epicurus rejected it? Don’t everyone jump at once.
Joshua:
I think there’s an interesting analogy here between infinite divisibility and — I don’t even know if I want to go down this line, but — one of the things that is absolutely core to Epicurean physics is an acceptance of a controversial idea: the infinite regress of causation. Much of medieval scholastic church logic and theology is based on the idea that an infinite regress of causation is not possible. But in Epicurean philosophy, an infinite regress of causation is not only possible — it is the means by which things happen in nature. Things happen as the effect of a cause that was itself the effect of a different cause, and that goes on backwards forever. There’s no point at which that wasn’t happening. That led, I think, to the condemnation of Epicurean philosophy by people like Thomas Aquinas. In his famous Five Proofs for the Existence of God, so much of the core is this idea that you can’t have an infinite regress of causation, and there’s something about an infinite regress that makes it more objectionable in the minds of people like Thomas Aquinas than the idea of a first cause — which you also get from Aristotle.
Cassius:
Joshua, just to make sure we don’t confuse anybody — what’s the difference between this infinite regress of causation, which is part of Epicurean philosophy, as opposed to the indivisibility of atoms, which Epicurus affirms?
Joshua:
You know, Cassius, as soon as I started that tangent, I thought, this is really not relevant to anything we’re talking about. But I think it’s actually importantly relevant, because it isn’t an interesting apparent contradiction. People would think: Epicurus says there’s no first cause, the universe is eternal, it had no beginning — so therefore there is an infinite series of causes extending back infinitely in time. He’s adopting an infinite regressive causation as a rejection of a first cause. Because if you’re going to reject first cause, then you’re left with: there was no first cause. Everything has been going on in sequence for an eternity — that would be his position.
The connection would be that in the view of Epicurus, you cannot have things happening like this for an eternity unless there’s a fundamental stability in nature. That fundamental stability derives from the indivisibility — the “uncuttability” — of the atoms. The word “atom” means in Greek “uncuttable.” The view of the Epicureans was: if the first beginnings, the seeds of things, can be degraded entirely out of existence, then there is no stable foundation for the infinite regress of causation.
Cassius:
Joshua, I am very glad you went down that road and did not stop. This is very useful for people to think about, and it kind of makes it clear: if you’re going to reject a first cause, the logical conclusion is that there was no first cause, which means the causes have been extending back into time through infinity. And if that’s the case, you still want some mechanism by which these causes have been operating through eternity, and that mechanism is these indivisible corporeal existences — the atoms themselves. Obviously there’s no God supervising or being the mechanism for this causation, and there must be something else. So that’s the importance of atoms. Not so much a matter of how big they are or whether in the end we think there are multiple subatomic particles — but if we are to reject the idea of a first cause, a lot of people are going to insist they need an explanation for it. The idea of a first cause is so deeply rooted in Western philosophy that taking a position on it is vital, I would think, to a consistent philosophy. At least it is to me.
This is why atomism remains for me a core of my viewpoint of why Epicurus is ultimately correct: I can’t handle not taking a position on whether there was a first cause. If I think there was a first cause, then I’m going to go into the monastery and devote my life to studying religion. But Epicurus is arguing that there’s no logical reason to do that — it makes perfect sense that there be an infinite regression of causes without a first cause, based on atomism as the mechanism.
Martin:
I agree that this makes the ancient metaphysics consistent.
Joshua:
There’s a notable story or joke in the physics community which Martin will certainly be familiar with — the story of the scientist giving a lecture on physics, and an elderly Indian woman comes up to him afterwards and says, “You know, everything you’ve been saying is wrong. Everyone knows that the earth actually sits on the back of four elephants, and the four elephants stand on the back of a giant turtle.” And the scientist sees an opening and says, “Well, what does the turtle sit on?” And the lady says, “You’re very clever, sir, but it’s turtles all the way down.”
Cassius:
It’s taken on a life of its own on the internet. I see it all the time.
Joshua:
I think the key issue about atomism — and what we have to understand about the text we’re reading — is that if atomism started with Democritus or Leucippus, we don’t have surviving works from either of them. So this letter we’re reading right now is sort of the ur-text for atomism in the ancient world. I think it’s probably the oldest surviving text on atomism. And what we’re really dealing with here is what George Santayana called “the greatest idea that mankind has ever hit upon” — the idea of atoms and void, that the atoms are eternal and the void is infinite. George Santayana — S-A-N-T-A-Y-A-N-A — was a Harvard-educated philosopher who taught at Harvard. He put this in a book called Three Philosophical Poets, in which he compared Lucretius with, I think, Dante and Milton — I’m not entirely sure who the other two were — but certainly the longest portion of his book is dedicated to Lucretius, which I think reflects the particular affinity Santayana had for Epicurean physics.
Maybe we should talk about what it is about atomism that makes it such a powerful understanding of physics for philosophy. Even if, as you say Cassius, there are some things that don’t quite match the way science sees things now, what is it philosophically about atomism that makes it so powerful? Is it just what we’ve been talking about — about infinite regress and how it cuts off any possibility of religion running things?
Cassius:
That’s exactly the question I’d like us to focus on. I think part of the reason we don’t think of atomism that way anymore — as the greatest idea ever hit upon — is that we’ve gotten jaded. We’ve learned so much about the details that we’re now familiar with the topic, and we don’t anymore think as much about the implications of it as they did back then. They were faced so closely with the immediacy of religion that had permeated all of society. And atomism as an approach is probably the ultimate alternative to supernatural explanations for the universe. Looking for these causes in the elements in nature has tremendous implications for a person’s worldview.
One of the things I’m always taken back to is a phrase in the New Testament — I think it was Paul accusing non-Christians of being “the slaves of the weak and beggarly elements.” And I think ultimately that’s the level of issue we’re talking about: people who are not willing to accept a natural explanation for the universe consider these atoms to be gods of their own. They think there’s no way to analyze anything except in terms of supernatural powers, and they think you’re just transferring supernatural power from Jehovah to the atoms or to dirt. So yeah, I think this is really the issue we have to grapple with.
Joshua:
I think you’ve hit upon something we tend to overlook, which is that atomism has teeth. It really does. It’s not just philosophically powerful — it presents an amazing challenge to established religious authority, not just in the ancient world, but as late as 1874, when John Tyndall gave his Belfast Address. In it he outlines not merely an argument for a scientific approach to the study of nature, but for a materialist understanding of nature, which he bases on Epicurus and Lucretius in particular. The evidence of atomism’s teeth is the sheer outrage that was caused by this address, and the backlash he received — as late as 1874. It really does present a tremendous challenge to the worldview of creation and design.
In my view it just short-circuits the requirement. Thomas Aquinas, when you look at his logical syllogisms for his Five Proofs for the Existence of God, what he ends up doing is affirming the consequence — he assumes what he has not proved. He also contradicts his own premise in his conclusion: he says that things have causes, that there cannot be an infinite regressive causation, therefore there is a first cause, an uncaused cause. But his first premise is that everything has a cause, and his conclusion is that there’s something that didn’t have a cause. So atomism just skips right through all of that, and does it in a tremendously powerful way with great explanatory power.
Martin:
Yes, and now the extra physics point. From a phenomenological standpoint, you can make continuum theories about a lot of things, and you have empirical constants which describe things, but you don’t come down to a mechanistic description. Something as seemingly simple as a phase transition — from one phase to another, or why there is anything other than a uniform solid body or a uniform fluid — is very difficult to describe mechanistically without referring to a smallest unit that still behaves like that substance. Once you cut it, it becomes something else. And things like overheating or undercooling — in a continuum theory you just don’t have a mechanistic explanation for how that can happen. With an atomistic theory, it’s relatively easy to come up with qualitative models. You can refer them back to primary principles and are not just relying on empirical constants, but on factors you can calculate from a small set of fundamental constants. I think this explanatory power in physics also translates into being powerful in philosophy.
Cassius:
I see what you mean. As opposed to a mechanistic universe, you’re dealing with something like a probabilistic universe — would that be an appropriate way to describe it?
Martin:
That would be another aspect — I didn’t mean that one, but it fits in as well. If we go into thermodynamics or quantum theories, we come to the need for a probabilistic description. But I was pointing toward a mechanistic explanation of phenomena — that a lot of effects fundamentally need atomism to get a conceptually understandable explanation, and continuum theories simply do not provide that. They have their place in a lot of physics, but when we really want to know what’s happening at the smallest scale and explain certain phenomena, atomism can explain it and continuum theories alone cannot.
Cassius:
I don’t know how far down that line we want to go, but I do want to go far enough to connect what you just said, Martin, to the ancient viewpoints. Wasn’t there a plenum issue even in ancient philosophy? I think the word “plenum” is associated with somebody — but maybe we won’t go too far down that road if we can’t.
Joshua:
A plenum is a space completely filled with matter — there’s no void in a plenum. The argument was made that in a plenum, motion would be impossible, and we observe motion, therefore we can’t be in a plenum. But the counterargument was made that as long as objects in the plenum move simultaneously, you can still have motion without a void.
Martin:
If you add compressibility to the continuum, it works as well. If you look at a slow-motion picture of someone getting hit by a fist or a ball, their face is probably temporarily deformed — that shows, at a phenomenological level, that things can be deformed temporarily and then spring back. So you can have that without requiring void.
Cassius:
I think that argument is mentioned in Lucretius as well. Martin, let me ask: does the continuum argument have any implication for whether there was a first cause or not?
Martin:
Modern physics is actually agnostic on this one. Whether there was something supernatural that made the world into this or not is completely irrelevant to the physics. We provide a natural explanation for things, which doesn’t need supernatural instances, but we don’t derive any conclusive position about the supernatural — that’s outside the level of concreteness of science itself. That’s then what we do here in philosophy: we draw the conclusion that because we don’t need it to explain anything, why come up with the supernatural?
Cassius:
I think Epicurus would answer that question: he’d say of course you need it in order to live a happy life. But I think that is the big difference between Epicurean physics and modern physics. Modern physics uses the word you used — agnostic — and it’s a great word. Modern physics doesn’t seem to want to campaign on these issues, although individual modern physicists certainly do. Whereas Epicurus waded right in, and saw it as a large reason for what he was doing in order to live happily.
All right, I promised we’re going to try to move faster today. Let’s move forward to section 42: “Moreover, the universe is boundless, for that which is bounded has an extreme point, and the extreme point is seen against something else, so that as it has no extreme point it has no limit, and as it has no limit it must be boundless and not bounded.” Doesn’t that strike you as just an absolutely logic-based argument from definitions — not even really physics?
Martin:
He’s showing something is self-consistent. It’s not really proving anything other than that this is self-consistent.
Cassius:
It’s almost like the definition of “boundless” — it does not have an extreme point, because that’s the definition of the word “bounded.” And it’s linked to an observation because he says “the extreme point is seen against something else.” So maybe it’s a combination of a logic argument and a sensation-based argument backing it up.
Joshua:
There’s also a sense here in which he’s beginning by just defining his terms, which is often an excellent starting place for explaining anything. Not just what “boundless” means, but the implications of it. And yes, he’s not giving the classic sense-perception-based argument on this question, but the classic thought experiment is the javelin throw — standing at the edge of the universe. Does that come from Lucretius?
Cassius:
I believe it’s in the parallel section of Lucretius, exactly parallel to what we’re talking about now. You’re taking the sense perception of watching what happens when you throw a javelin — it hits something solid, or it doesn’t — and arguing by analogy, by way of thought experiment, to what would happen if you stood at the edge of the universe and threw a javelin. Either it hits something, in which case there’s body outside the universe, or it doesn’t hit anything and keeps going, in which case there’s void beyond what we had assumed to be the limit.
Martin:
Yes — it’s a good one.
Cassius:
Section 42 continues: the infinite is boundless both in the number of bodies and in the extent of the void. He’s saying it’s boundless not only in extent of space but also in the number of bodies it contains. His explanation is that you have to have both for things to work — otherwise either the space would take over from the bodies, or the bodies would take over from the space.
Joshua:
Not just for everything to be in balance, but for things to match the observable universe we actually see.
Cassius:
His view is that you don’t get something like a tree if all the atoms that would go into making a tree are scattered over ten million light years of space. They have to come together in a space to do that, and in order to do that there have to be a sufficient number of atoms in any given volume for them to have even the remotest chance of coming together. An infinite void with a finite number of bodies means they scatter — the distance between atoms just gets further and further apart as time goes on.
Joshua, here’s an easy question: is there a difference between infinite and boundless?
Joshua:
No — not really.
Martin:
No difference.
Cassius:
I agree. But what I wanted to pin down was this implication that “boundless” means uncountable. The word “infinite” does not imply some kind of mystical thing. You can’t count them because of the limitations of your sensations and your lifetime. It’s not that there are new things being brought into existence every moment — they actually do exist even though the number of them is uncountable. Is that correct?
Martin:
You’re going to tempt me to go into a long tangent about how modern physics would say something different, but at least in terms of ancient philosophy or common sense without quantum mechanics —
Joshua:
Yes — particularly in terms of space, my day job involves taking very large measurements using very precise equipment, but on any given line you take, that line goes out infinitely in that direction. I see where you’re going with the concern, though — some people have a concern that describing something as “infinite” is just what you’d describe God as. As if by designating it as infinite you’ve somehow invested it with a supernatural quality. And in the Platonic dialogues you’ve got the argument that pleasure can’t be the highest good because pleasure has no limit, and something that has no limit can’t be the perfect good.
Cassius:
That’s right. So the basic point: he uses words we would translate as “infinite,” but he’s equating the infinite with “boundless” and “unlimited in number” — not implying that things are obviously coming into or going out of existence, because he’s already established that they don’t.
It is interesting to me because the idea of boundaries comes up quite a lot in Epicurean philosophy. In Lucretius, you’ve got that paean to Epicurus in which he says Epicurus traversed the “flaming ramparts of the world” and brought back news of what can be and what cannot, and said “the boundary stone set forever.” There is a sense in which the Epicurean project — not merely as a means to pursue happiness but as a method of inquiry — is to find out about boundaries: the limits of pleasure, the limits of divine involvement in human affairs, the size of the universe. And probably one reason for that is that we want confidence in ruling out certain things that threaten our happiness — such as the idea of capricious gods supernaturally controlling our fate.
One reason I articulated that poorly formed question earlier was that in the next paragraph, the word that jumps out at me is “incomprehensible.” He calls the number of varieties of shape “incomprehensible in number.” The last sentence states it clearly: in each shape, the atoms are quite infinite in number, but the differences of shape are not quite infinite, but only incomprehensible. Lucretius makes the comparison between atoms and the building blocks of language. That doesn’t quite work when your language only has 26 letters, because 26 is not incomprehensible. But I think of a language like classical Chinese, with an amazing variety of characters. I read a story once about a professor of Chinese at a major Chinese university who asked graduate students — people who had chosen to study this language at a postgraduate level — whether they could give the Chinese ideogram for the word “sneeze,” and not a single one of them could. So that’s a language where the variety of characters is such that no one person knows all of them. If I was going to take Lucretius’s analogy between the shapes of atoms and the letters of the alphabet, I would have to reach for not an alphabet, but something like Chinese ideograms.
Martin:
Actually, we have a problem here — there are contradictions between the translations. The Hicks translation looks correct, and the German translation makes sense as well because it goes along the line of Hicks. But Bailey’s translation contradicts itself, and Yonge has the same problem as Bailey. In that last part of the sentence, if the varieties of shape are “limited in number,” then in Bailey’s translation the number of different shapes comes out as infinite — and that doesn’t match the other translations, and it doesn’t fit the overall meaning. From the translations that make sense, the number of different shapes is expected to be finite, because we can use the same argument here: what we see is a great variety of things, but not an infinite number of things. So we don’t need an infinite number of different atom shapes.
Cassius:
Thank you for pointing that out, Martin. This is probably a time I should have mentioned earlier: when you compare Hicks and Yonge, it looks like Bailey is removing the parenthetical expressions that are in the original text. In comparing sections 42 and 43 in the Hicks or Yonge version, those contain parenthetical expressions such as “for neither does the divisibility go on ad infinitum.” We’ve been reading Bailey, and that’s one of the downfalls of using only a single translation.
Martin:
Because with another issue in section 43, there’s something important to know about what these parenthetical expressions are and where they come from.
Cassius:
I think they exist in the current versions of Diogenes Laertius, and certain sections are obviously added on by commentators over the centuries — for example when it clearly says something like “he says below” or “he adds.” That’s clearly not part of the original letter. These comments are ancient in origin apparently, but who knows whether they are by Diogenes Laertius or by somebody else, and by an Epicurean or not — a different level of reliability comes into play.
Joshua:
There is a sense in which putting something in parentheses is a modern convenience of punctuation. Most ancient Greek texts were written as a continuous stream of capital letters with no spaces and no punctuation marks. This idea that we could write in a way that is very clear and legible with different things set off and delimited is a relatively modern convenience — it didn’t exist in the ancient world. There’s a style of writing called scriptio continua — writing without spaces or other marks between words or sentences, and also without punctuation, diacritics, or distinguishing letter case. Interestingly, the oldest Greek and Latin inscriptions used word dividers to separate words and sentences, but classical Greek and late classical Latin both employed scriptio continua as the norm. That’s not the progression I would have expected — they started with word dividers and then abandoned them.
Cassius:
This is a really interesting subject, and one of the ways it jumps into the highest-level view of all this is the principal doctrines — we always refer to them as forty, and we segment them up into forty, but apparently that segmentation did not exist in the original text. When you read them all as a narrative paragraph, it comes across differently than when it’s separated out, and whoever chose to make those divisions has inserted their thought process into what we’re taking today as gospel from Epicurus.
Joshua:
So much of how we write sentences today is derived from the humanist scholars of the Carolingian Renaissance and then the Italian Renaissance. For example, Poggio Bracciolini — the book hunter and papal bureaucrat who discovered Lucretius’s lost poem in a monastery in Germany — was known for having very beautiful handwriting, and it’s from him and people like him that we derive lowercase letters. They didn’t use lowercase letters in the ancient world. Getting people acclimated with the difficulties of transmitting text and understanding it was, in my case anyway, one of the first awakenings I had that there’s more to be understood here than meets the eye — when it comes to something like the Bible, a compilation of decisions by people over centuries about what books to include, how to read a particular section, how to divide it up and translate it.
Cassius:
Absolutely. And so I have to tell one of my favorite stories now. There was an early American businessman born in 1747 — his name was Timothy Dexter — and he had the reputation for being kind of a fool who just lucked into wealth and power. He had very little schooling and wrote a book called A Pickle for the Knowing Ones, which is sort of his memoir. But in this book there was not a single punctuation mark anywhere in it. The publisher got so many complaints that in the second edition, Timothy Dexter wrote a little paragraph saying: “People are having trouble reading this, so I’ve given you two pages of punctuation marks, and you can salt and pepper them as you please” — and he just tacked that on to the end of the book.
Joshua:
I’ve never heard that story. That’s very interesting.
Cassius:
Now I’m beginning to look at the clock. Let me go ahead and make this comment on section 43. It’s always been my understanding that the use of the word “swerve” here in Bailey is not the same as what is contained in Lucretius. I’ve always read that many people say the swerve does not appear in Epicurean texts anywhere other than Lucretius. Is that correct from what you guys understand?
Martin:
It’s not in the extant texts, so it’s pretty certain it was in those lost texts, but in the preserved texts — not here. This surprised me, not to see it here. But we also have here this issue that different translations don’t have it. Bailey has it in parentheses, and at least one of the others doesn’t.
Joshua:
Right — Epicurus certainly came up with it himself. It clearly dates to Epicurus. But the point is that it doesn’t survive in the preserved texts except in Lucretius. And the further point is that in Democritus’s physical universe — one of the founders or co-founders of atomism — his universe really was mechanistic and deterministic, with no room for free will. That’s a huge part of Epicurus’s version of atomism: there has to be room left for free will.
Martin:
Exactly. And adding to this — the German translation doesn’t even refer to this as the swerve. It uses a word more like “drifting,” which is different. That means there’s another discrepancy in the translation, and what is meant in section 43 does not use a word for what was then used for the actual swerve which Epicurus came up with. In that sense it probably wasn’t mentioned here directly.
Cassius:
Having made those comments, is there anything really important in sections 43 and 44 other than the issue of motion being something eternally going on?
Joshua:
Yes — and it’s one of the thorniest issues in Epicurean physics, one that I continually struggle with even trying to understand. It’s this idea of atoms falling straight down. Obviously what they lacked in the ancient world was any sense of gravity as a force of attraction between bodies, and so no matter which physical system you look at you have to somehow account for the fact that if I push a book off a table, it falls to the ground. Aristotle thought that the center of the earth was the center of the universe, and the natural tendency of dense bodies was to go toward the center. And then you see in Epicurean physics this idea that originally the atoms were falling straight down, and then you had to have the swerve in order to get them to start colliding with one another. To me that is the most fundamental contradiction, because there is no original state in Epicurean physics — there’s no time when things were just first starting to happen. They’ve always been happening. So this idea of atoms raining straight down seems very odd and confusing to me.
What I would say about it is that he had a pretty clear playing field where he had already affirmed the universe is boundless in all directions, so there’s nothing at the bottom — nothing below us that would be attracting. But on the other hand he can observe here on earth that everything does seem to fall downward, and when you combine those two observations you simply have to start with the presumption that everything is constantly falling in a particular direction.
Martin:
But that’s not correct — if you look up at the sky and see the movement there, it goes in circles or sideways. The clouds go sideways.
Joshua:
As I say, it’s tremendously confusing — because there’s no original state, and also because there’s no center to the universe. It’s difficult to understand why there should be a particular favored frame of reference. To say there’s no center and no limit, but for some reason we know that “that way” is down and that the natural tendency of bodies is to go down — there’s a genuine inconsistency in Epicurean physics. There’s no way to get around it when there’s no theory of gravity. When there’s no understanding of gravity as a force that moves bodies, there’s simply no way around this problem, unless you take the Aristotelian view that the universe has a center and that the tendency of bodies is to fall toward that center.
Cassius:
Regardless of how you unwind that, I agree with the direction you’re taking, Joshua. You’ve got to start with the premises he’s previously established — that there was no original state, that nothing has ever changed about the way things are as a whole, so you have to take that as a starting point of his thought. There is more detail in Lucretius about this section as well, but it’s not satisfying. I’m not satisfied with it either and can’t explain it. If I were being asked this by some child in my hypothetical kindergarten, I’d go in that direction: it’s very difficult to understand, but there are certain things you have to take as a given — that there was no beginning to the universe, which means whatever has been happening has been happening eternally, and you’re also taking as a given in Epicurean philosophy that there’s no center and no limit downward to the universe.
But “these brief sayings, if all these points are borne in mind, afford a sufficient outline for our understanding of the nature of existing things” — that’s a great summary of this passage and a good reminder that what we’re dealing with is an outline, the Epicurean conception of nature. If you want to read everything Epicurus had to say about nature, you’re going to need a time machine. And when you come to a position like the atoms falling through the void eternally, you can take the position that there’s a lot more to understand than we can unwind right now, and you can wait — as is discussed in Diogenes Laertius, that Epicurus suggested when we don’t have enough information we wait before we take an arbitrary position about the right answer. We can move on with our lives and attempt to live them happily. Or else we can go off and decide that Jehovah has a better answer, and as far as I’m concerned, Jehovah does not have a more satisfactory answer than Epicurus. That’s the kind of question he’s posing to everybody, and each person has to decide for themselves.
Martin:
I just want to add something here. What I found in the German translation is that it doesn’t talk about “downward movement” — it uses a phrase more like “perpendicular path.” So instead of falling downward, the German translation gives “moving on a perpendicular path.” Perpendicular to what, it doesn’t say. So it doesn’t really resolve the issue — there’s still some sort of reference direction, but nothing to pinpoint it to. The contradiction is not really removed, but it doesn’t carry this implication of “down.”
Joshua:
I think we’ve done a good job getting beyond just the physics into the implications of the physics. Some things are going to remain inexplicable. Maybe the key thing to end with is that this issue of falling down — it’s not as if when the theory of gravity was formulated that was a death knell for Epicurean philosophy. There’s no reason it can’t keep going strong, even with a changing idea about how the universe operates.
Cassius:
I would definitely agree with that. Well, that’s a good place for us to stop. We’re going to take the material we’ve just gone through and apply it to all sorts of questions over the next several weeks — how our sensations work, how many worlds like ours there may or may not exist in the rest of the universe, and many other questions. We’ll take these building blocks and apply them to practical questions, beginning next week. And hearing nothing else, I thank you for your time today, and we’ll come back next week.
Joshua:
Thank you.
Martin:
Good job.