Episode 115 - Letter to Herodotus 4 - Atoms, Void, and Basic Epistemology Issues
Date: 04/01/22
Link: https://www.epicureanfriends.com/thread/2442-episode-one-hundred-fifteen-letter-to-herodotus-04-atoms-void-and-basic-epistemo/
Summary
Section titled “Summary”Martin reads the same physics section again (sections 40-45), and discussion focuses on the opening claim that “body exists since itself witnesses in the experience of all men” — what it means to ground reasoning about the imperceptible in the universal testimony of sensation. The panel examines how Epicurus differs from Plato and Aristotle in his treatment of sense perception: Plato’s cave analogy undermines the senses as unreliable pathways to truth, while Epicurus insists that sensation is the ultimate standard for all reasoning including about atoms and void. Joshua tells the story of Giordano Bruno being burned at the stake in 1600 in part because atomism was incompatible with the Catholic doctrine of transubstantiation — if the bread is already nothing but atoms and void, it cannot be transformed into the flesh of Christ. Vatican Sayings 29 and 45 are read to underscore the egalitarian character of Epicurean knowledge: nature is explicable to all men, not just the philosophical elect. The group discusses the Democritus formula (“by convention sweet… in reality atoms and void”) versus Epicurus’ position that sensation is primary and real, and closes with the observation that physics and epistemology must be studied together because each provides a check on the other against both uncritical credulity and the paralysis of absolute skepticism.
Transcript
Section titled “Transcript”Cassius:
Welcome to Episode 115 of Lucretius Today, a 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 Epicurean texts 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 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, discussing some basic epistemology problems along the way. Now let’s join Martin reading today’s text.
Martin:
Moreover, the universe is bodies and space, for that body exists is witnessed by sensation itself in the experience of all men, and in accordance with the evidence of sense we must of necessity judge of the imperceptible by reasoning, as I have already said. And if there were not that which we term void, and place, and intangible existence, bodies would have nowhere to exist and nothing through which to move, as they are seen to move. And besides these two, nothing can even be thought of either by conception or on the analogy of things conceivable, such as could be grasped as whole existences and not spoken of as the accidents or properties of such existences.
Furthermore, among bodies some are compounds and others those of which compounds are formed. 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 the 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:
Martin, thank you for reading that for us today. Anyone following along sequentially is going to have heard this section read several times, and that’s probably a good thing rather than a bad thing — because Epicurus is saying in line 45 that “these brief sayings afford a sufficient outline for our understanding of the nature of existing things.” This is a particularly important list of principles for Epicurean philosophy.
Part of the reason we’ve continued to read them each week is that we haven’t made as much progress going through them as quickly as we might have liked — and we’ll see how that goes today as well, because there’s some material here in the first several passages that I think really deserves us lingering over. We’ve continued to do a pretty good job of not spending all the time talking about how what is being said comports with modern physics. We’ve attempted to talk about the implications of these principles as Epicurus would have seen them and get into the meat of how Epicurus was using them himself, since he was primarily looking at teaching people how to live happily and not teaching people how to be the best astrophysicist they could possibly be.
And the very first sentence here — “Moreover the universe is bodies and space” — is followed by the part I think is more important: “for that bodies exist is witnessed by sensation itself in the experience of all men, and in accordance with the evidence of sense we must of necessity judge of the imperceptible by reasoning.” The point we should talk about is not so much the conclusion that everything is made of atoms and void, but how he reached this conclusion — because he’s stating the basis for it, and that basis is sensation itself in the experience of all men.
What’s the difference between atom and body here, Martin?
Martin:
What we can see and what we can feel to the touch — anything that has mass, in a generalized sense, since photons don’t have rest mass but do have mass when they move. So bodies are essentially what’s made up of atoms — every collection of atoms. But he doesn’t say “atom” in this first paragraph yet. Here he stays closer to the sensation: what we perceive are not individual atoms, but what is made of them.
Cassius:
Right — the word being used here is not “atom” but whatever is perceptible to the senses. He’s explicitly linking to the experience of all men: “sensation itself witnesses in the experience of all men.” So he seems to be making a pretty broad generalization that our senses are sufficient for us to determine that something out there exists in the universe. And then he says, “in accordance with the evidence of sense, we must of necessity judge of the imperceptible by reasoning.” So what other possibilities are there for judging of the imperceptible, Joshua?
Joshua:
Well, that is essentially the only method, because by definition we cannot perceive what is imperceptible. The only method we have to get at it is by observing things that are perceptible and determining to what extent things which are imperceptible are analogous to things that are perceptible, and reasoning from the perceptible to the nature of the imperceptible. There wouldn’t be another way to go about it.
Cassius:
The reason I’m asking is: if he’s talking to some new student in Athens who has been going around from school to school, what are the other competing possibilities that other philosophers would say should be used instead of the evidence of sense?
Joshua:
Well, in this as in most things, you’ve got a variety of competing philosophical views. One would be arguing from pure mathematics and the logic of pure mathematics — the Pythagoreans probably would do that. And of course, Plato spent quite a lot of time talking about things that were imperceptible. My understanding is that his ideal forms, the world of ideal forms, was imperceptible. But then, what was his source of knowledge about this?
Cassius:
That’s the challenging question. Reasoning about them — so in the end Plato has to come down to what the real world is, and he says what we see is just illusion and behind it are these ideal forms. And by reasoning, he can come up with ideal forms which would then be behind those illusions. But here in this sentence, Epicurus himself says that we must of necessity judge of the imperceptible by reasoning. So how is that different from Plato?
Martin:
The big difference is that Epicurus puts more emphasis on our perception and our sensation. He gives perception a higher level of reality than Plato admits to it. Epicurus starts from the perception, and the reasoning then must be consistent with what we perceive. For Plato, what we see is already illusion — so the senses provide no firm starting point.
Cassius:
What if somebody said to you that it’s totally different — that Plato undercut the senses and said that the senses are not sufficient for reliable reasoning and that they’re so deceptive they should be thrown out as indicators of reliable reasoning? Is that not Aristotle’s position as well? Is that not what led Pyrrho to his conclusion that there was no reliable method of reaching any conclusion at all — because they all attacked and undermined and threw out the reliability of the senses?
Joshua:
I think that in the case of Plato in particular, the attainment of virtue is instrumental in attaining any understanding of what he thought to be imperceptible — his world of ideal forms. Not just everybody is going to do this. Not everybody can, I think, in Plato’s view. This is a big difference. Plato was far more elitist in that sense — only the philosophical elect can penetrate through the illusion to the real.
Whereas — here’s Vatican Saying 29, which seems relevant: “To speak frankly, as I study nature, I would prefer to speak in oracles that which is of advantage to all men, even though it be understood by none, rather than to conform to popular opinion and thus gain the constant praise that comes from the many.” So Epicurus is saying that he is going to approach nature with the view that she can be understood, and understood in essentially all her particulars, and explained not just to philosophers but to all men and women. The idea that there’s a realm of higher knowledge cordoned off only for the wise is not consonant with Epicurean philosophy. It starts right here with atomism and void.
Cassius:
Joshua, what you just said I think is something we all agree on — that Epicurus held that knowledge is possible. Summarize the point: what’s the difference between Epicurus and Plato?
Joshua:
Part of the difference is that whether or not the world is explicable for Epicurus depends merely on your ability to look at the facts dispassionately and to reason from the perceptible to the imperceptible — restraining yourself from going too far. Epicurus is not going to reason his way to a supernatural creator God because that would be something imperceptible, but one to which the perceptible gives no path. And how would Plato object to Epicurus’ perspective? Plato had the view quite different from Epicurus — not only are most people not going to approach an understanding of the way things really are, but the whole world that we see is actually false to the way things really are. You’re looking at the dream, not real life. And there’s only a select few who are ever going to see through it. That’s what the cave analogy is saying — all we really can see is shadows flickering on the wall. There’s some other pure world of ideal forms that we can’t see, and it takes a certain kind of spiritual insight to see it. In Plato’s view.
Cassius:
I’ve always thought the big issue here is the question of how much we can rely on our senses. Plato’s cave analogy seems intended to display that our attempts to use our senses to determine truth is doomed to failure because the senses are ultimately insufficient to allow us to come into contact with truth — that something more than our senses is needed. Now, another way of asking: would Plato or Aristotle even agree with the sentence “in accordance with the evidence of sense, we must of necessity judge of the imperceptible by reasoning”?
Martin:
In the end, both of them need to come up with their ideal forms or whatever in a way that explains the illusions. So they use reasoning as well, but they use it only as much as required to explain those illusions with their ideal forms. Whereas Epicurus takes the sensations more seriously and makes them the foundation — his concept is much closer to the sensations than Plato felt compelled to be.
Joshua:
Yeah, I think it’s the case that Plato is not relying so much on the senses. There was that famous inscription over the door to the Academy: “Let none who have not studied geometry enter here.” The implication was that in geometry, you can start with an axiom and reason your way to new information without any sensory input at all. Geometry does not require sensory input — you just have to start with definitions. “Two points make a line” — from there you can reason your way to further propositions. At no point in the process do you ever have to get involved in the world of the base senses. So in Plato’s view, sense perception is not a vehicle for getting from the phenomenon to the ideal form.
And in the view of the Roman Catholic Church in the Renaissance as well. Giordano Bruno was executed at the stake in the Campo de’ Fiori in Rome by Cardinal Bellarmine, and among the many charges leveled against him, one was his lack of orthodoxy on the Eucharist — specifically the Catholic doctrine of transubstantiation. The Vatican held the view that if the universe is made of atoms and void and nothing else, then the bread at the Eucharist and the wine are made of things that are not bread and not wine — because there’s no “bread atoms” and no “wine atoms,” it’s just the same atoms that everything else is made of. And so the argument they made was: if there’s no bread substance in the bread, if the bread is already just atoms like everything else, then it cannot by the act of transubstantiation be transformed into the flesh of Jesus Christ. So one of the reasons he was burned at the stake was for atomism — because the idea that the universe is explicable to people of ordinary sense is not something the Catholic hierarchy was prepared to accept.
Cassius:
Joshua, that is a fascinating story, and I think it is directly applicable to what we’re talking about. I don’t think I’ve ever read that before. Is there a particular source?
Joshua:
The Vatican has records of the trial, which went on for quite some time, and the various interpretations of it are occasionally in conflict — sometimes the Catholic Church will say he was executed for this reason, not that one. But when you read these documents, the charge of atomism was plainly made. I will attempt in the show notes for this episode to provide a source for that claim.
Cassius:
That’s exactly what I was about to say — please do put that in the show notes. I’ve always thought that the epistemology issues are some of the least well-developed parts of Epicurean philosophy in our normal discussions, and even after years of attempting to do better at it, I am far from being where I need to be in terms of articulating this. The role of sense perception is critically important in understanding Epicurean epistemology and in explaining how he differs from Plato and Pythagoras and probably even from Aristotle. Yet it’s not easy to do. I can’t even point to some very clear statement of Plato’s view on the subject or Aristotle’s view — and without being able to line them up clearly against each other, it’s hard to bring them down into understandable form.
Most people who’ve read anything about Epicurus know that he supposedly said that all sensations are true and that he stresses sensation. Most people have some sense that sense perception is very important to Epicurus. But unless they can distinguish how that differs from Aristotle and Plato, they’re not going to be able to get much further in understanding Epicurean epistemology. So we’re not going to be able to resolve today what the best way of understanding this is, but it is something that would be worth a lot more time for anyone who wants to really develop their understanding of Epicurean philosophy.
Joshua:
Let me bring in one more of the Vatican Sayings here, with the usual disclaimer that we don’t actually know that all of these were written by Epicurus himself. Vatican Saying 45: “The study of nature, which is what we’re trying to do here, does not create men who are fond of boasting and chattering or who show off the culture that impresses the many, but rather men who are strong and self-sufficient and who take pride in their own personal qualities, not in those that depend on external circumstances.”
While the end of that saying is a little more difficult to apply to what we’ve been talking about here, I think it does apply. What he’s saying is that it doesn’t matter what kind of person you are — you could be the worst person there is and still study nature and still come to something approximating the way things really are. You could come to a real understanding of how nature works without being good, without being virtuous, without being wise. You don’t have to be those things, because the evidence you need is all around you. You just have to pay attention to it. Whereas if you take the Platonic view that there’s a world of ideal forms and only a select few philosophers will ever penetrate to it, that is selected only for the few and the rare. You don’t have to be a philosopher to understand the Epicurean physical world. It doesn’t take a great deal of learning. You’re not being sold a bill of goods.
Cassius:
Joshua, let me bounce off of what you’ve just said. At some point today I was going to work this in. There’s a parallel to the passage we’re reading here — “sensation itself witnesses in the experience of all men” — in Lucretius Book 1, line 418, which reads: “For that body exists is declared by the feeling which all share alike.” And it’s that “all share alike” that brought that to mind — you’re talking about how all men have this kind of reasoning available to them just by using their senses. Lucretius put it: “For that body exists is declared by the feeling which all share alike. And unless faith in this feeling be firmly grounded at once and prevail, there will be nothing to which we can make appeal about things hidden, so as to prove anything by the reasoning of the mind.”
So again, Lucretius expands a little bit on what Epicurus has said, and says: unless faith in this feeling be firmly grounded at once and prevail, there’s nothing to which we can make appeal to make arguments about things which can only be reasoned about because we have no direct evidence. And that takes me back to the quote from Torquatus we have at the top of the EpicureanFriends.com forum right now about how the constitution of the world must be thoroughly understood before you can justify the verdicts of your senses.
Cassius:
So maybe we should go past the first sentence of our material today. Section 40 is about the void — that there must be a void, because if void did not exist, bodies would have nowhere to exist and nothing through which to move, as they are seen to move. The argument against void was something called the plenum — the idea that if matter is crammed together with no empty space in between, motion is still possible because things in front of you will just move out of the way, and then fill in the space behind you. So void exists in Epicurean cosmology in part because it allows for motion, which otherwise would seem to be impossible.
Joshua:
Exactly. And then the next sentence goes far beyond that: “Besides these two, nothing can even be thought of either by conception or on the analogy of things conceivable, such as could be grasped as whole existences and not spoken of as the accidents or properties of such existences.” What I read that to assert is that there is nothing besides atoms and void. Atoms and void and nothing else — that was said to be a kind of Epicurean mantra.
Cassius:
Do you remember where you read that?
Joshua:
It’s in Stephen Greenblatt’s The Swerve, which I think a lot of the claims made both by Greenblatt and DeWitt about the practices of early Epicureans should be taken with a grain of salt. It’s somewhat speculative. But I think it’s accurate. And that “nothing else” is really extremely important. What Epicurus is asserting when he talks about “whole existences” is that atoms are whole existences — they exist in themselves and they are irreducible. Everything else that you think exists is actually just a property or an accident — what Lucretius calls an eventum — of the mingling of atoms and void. What we would say today is: a particular configuration of matter and energy. So something like mind, which for many other philosophers seems to have an independent existence, an incorporeal existence — for Epicurus there is no incorporeal existence other than void, which is just space.
Cassius:
Before we go further, Martin — any initial reaction to that sentence?
Martin:
I have nothing to add at this point. Because it’s not really a physics sentence — it’s more of a logical assertion.
Cassius:
I agree — because when you’re talking about nothing that can even be thought of by conception or analogy that could be grasped as a whole existence, you’re almost by definition talking about something imperceptible. So we’re in the realm of logical assertions. One of the problems with life in general is that it’s not possible to prove a negative — you can’t prove that X doesn’t exist. But what you can say with reason is that if X did exist, it would leave certain fingerprints on the universe, and since we don’t perceive those signs, we can conclude that X does not exist. Epicurus is going even farther and saying: nothing can even be thought of by conception or analogy that could qualify as a whole existence — everything else is just an accident or property of atoms and void. And I think one reason people should be interested in this is that it has a deep connection to what Democritus said. There’s a famous quote from Democritus: “By convention sweet, and by convention bitter; by convention hot, by convention cold; by convention color. But in reality: atoms and void, and nothing else.”
Joshua:
That formulation from Democritus is broadly consistent with Epicurus, but there’s an important nuance. The issue of the swerve is the main distinguishing factor between Democritus and Epicurus — in Democritus’ physical universe, the motion of atoms is mechanistic, and the implication is that there was no free will. The swerve is the big distinguishing change Epicurus made to the Democritean system. And there’s that remark by Cicero that all of Epicurus’ science came from Democritus except the parts he changed, and those parts that he changed is where he went wrong — or something to that effect.
Also, I think you’d want to be careful with Democritus’ “by convention” versus Epicurus’ actual view. Epicurus would certainly agree that there are no “sweetness atoms,” but I don’t think he would say that the sweetness we taste is therefore just a convention. It’s real to us — it’s what our senses report, and our reality is nothing but those things we can perceive. If we can’t perceive it, it’s in some sense unreal to us.
Cassius:
Yes — I think that’s Epicurus’ point. Only atoms and void have eternal existence that does not change. But who cares about eternal existences that don’t change? I’m alive right now. We’re alive for 75 years or whatever. And what’s going to happen after we die and before we were born certainly has relevance to us in a sense. But only those things that exist while we’re alive enter into our own existences. So our reality is what our senses allow us to perceive. I have a quibble with that word “convention” — convention implies to me that it’s there because we agree on it. But it’s not there because we agree on it. It’s there because my senses tell me it’s there.
Joshua:
I quite agree. And to add another layer — we mentioned Cicero. He says something that we have on the homepage of EpicureanFriends.com: “You Epicureans round up people from all the crossroads — decent men I allow, but certainly of no great education. Do such as they then comprehend what Epicurus means while I, Cicero, do not?” So there isn’t an elitism about how people interact with the universe itself and whether they need to go through an intermediary — whether that be a Platonic philosopher, a church leader, or anything in between. Your ability to interface directly with the substance of the universe, even though much of it is imperceptible to you, is one of the great equalizers. The conclusion doesn’t arise because it’s attractive — the conclusion arises because it’s the nature of perception and the nature of the science that Epicurus holds that perception is the ultimate test of reality, and perception is what everybody has.
Martin:
The idea is that it’s egalitarian.
Cassius:
Egalitarian — yes, exactly. Well, we’re at a pretty high level right now talking about egalitarianism, and then the very next sentence goes right back down to “among bodies some are compounds and others are those of which compounds are formed” and we start talking about indivisibility. But we’re probably close enough to the end of a normal podcast episode that rather than go on further, we ought to think about what we’ve been talking about today.
These issues of epistemology are critical to Epicurean philosophy, and it’s easy to gloss over them and just move on. The discussion of epistemology is embedded in the discussion of the physics — which is something Diogenes Laertius points out, that the Epicureans did as a matter of course: they would talk about the physics and the method of thought at the same time. It makes sense to do that, but perhaps for some of us today it can cause us to gloss over the distinct issues of how to reason and what the nature of knowledge is, versus just the physics points.
Joshua:
I was thinking about how knowledge is filtered through other people, and it’s interesting to note those moments in history when the leader of orthodoxy — the person who holds an absolute hold on the truth — where it sort of changes overnight. Constantine at the end of the Roman Empire was one of these people. There’s a story — it is known that Constantine killed his son and his wife — the argument goes that after he killed his wife and son, he went to some pagan priests or elders and asked for absolution and they refused him. And then he went to the Christians and asked for absolution and they granted it to him. And so he converted to Christianity. That would be a very different story than that he won some particular battle because he saw a cross in the sky.
Cassius:
Yeah, and anyway — if you see a cross in the sky, or a rubber duck of monstrous size descending from the heavens — that’s still atoms and void doing what they do. If in fact something like that does happen and we determine through the senses that it has really happened, then we’d better deal with it. Epicurus would tell us to be careful about how we interpret it so that we’re not manipulated or taken by some kind of illusion. But ultimately, what we perceive through the senses is what we have to deal with — if it does happen, we’d better incorporate it. The ultimate test of reality is not our logical speculations about reality, but what we can perceive in our existence.
Martin:
Yes. Currently I wouldn’t say it any differently. There’s a huge distinction between not accepting everything we imagine as possible and not accepting things likely to happen — but ultimately we sort everything out according to the evidence of our senses. And every time we get up to this higher level of understanding about what’s going on, and then we look at the next line in Epicurus, it rivets us back down to atoms and void. Or rather, it rivets us to: you’d better have confidence in your senses to do your reasoning about everything.
Cassius:
Right — you need not only a method in terms of relying on your senses, but you also have to reach some conclusions about the nature of the universe in terms of atoms and void. They go together, which makes it logical to talk about them together.
All right, we’ve got to come to a firm conclusion for the ending of the episode. Joshua, maybe the ending should come from this point about how they go together.
Joshua:
I think it’s essential to combine physics and epistemology, because each one provides a check against the other. By having both in hand, what it really prevents is going off on a wild flight of imagination detached from any sense of reality. You need to have a sense of what’s in the universe and how it works, but you also have to constantly attend to the other part of the equation: how is it that you think you know what the universe is and how it works? If you go too far down the direction of just saying what’s in the universe without attending to how your knowledge of that is formed — which is from the senses — you can end up with a picture that doesn’t really resemble the way things really are. But the reverse is true as well. If you spend too long constantly being skeptical of how it is that you know what you know, you end up in the position of Pyrrho — that nothing is knowable — or the position of Heraclitus — that we cannot get to anything like true knowledge. It’s important to be skeptical to a degree about what we think we know about the universe, and we do that by restraining ourselves to the evidence of our senses and the reasoning we use to expand beyond that evidence. And then there’s the universe itself, which we’re trying to understand but will never understand if we can’t get the sense perception part right.
Martin:
I agree and have nothing to add.
Cassius:
Yeah, Joshua, I think what you just said is correct. And I realize it sounds like we’re struggling, but I’m pleased with this conversation even though we’re struggling through it. People listening to this discussion — me listening to you discuss it — it’s very helpful to me to try to piece it together in my mind. Because I do think this is an area that we really need to put more time into being able to explain to other people. Even though we struggled through some of this today, I think it’s very valuable. As we continue on next week, we’ll come back and continue to hit some of these same things. We need to be firm about what our position is on the role of the senses in Epicurean philosophy, and firm in articulating what we think is different between Epicurus’ approach and the approach of these other philosophers.
Joshua:
I am hesitant to say anything that will lead us right back into the problem. There will be plenty of time for that next week for me to put my foot in it.
Cassius:
Very good. I appreciate the time that you guys give as we produce this podcast. I think it’s very helpful, and we’ll come back and continue next week. So thanks very much.
Martin:
Thank you.
Joshua:
See you then. Bye.