Episode 263 - "All Sensations Are True"
Date: 01/07/25
Link: https://www.epicureanfriends.com/thread/4216-episode-263-all-sensations-are-true/
Summary
Section titled “Summary”Cassius and Joshua examine the Epicurean doctrine that “all sensations are true” — not as a naive claim that illusions never occur, but as a precise epistemological position: the senses report data faithfully; error arises in the mind’s judgment layered on top of that data. DeWitt’s article “All Sensations Are True” is the central scholarly reference, along with his Epicurus and His Philosophy, and his analogy of the mind as judge and the senses as witnesses is explored at length. Principal Doctrines 2, 22, 23, and 24, Lucretius Book Four (lines 353, 400, 418, 469, 478, 500), and passages from the Letter to Herodotus (Sections 38 and 52) are analyzed. The square tower seen as round from a distance, the colonnade appearing to converge, the bent oar, and the spinning children’s illusion all illustrate the same point: the sensation itself is not false — the error is in the reasoning applied to it. Philip and Estelle DeLacy’s Philodemus: On Methods of Inference provides Aristotle’s contrasting position. Cicero’s On Ends Book One, Section 71 (Torquatus’s closing appeal to the senses as “untainted and unblemished witnesses”) and the Thomas Jefferson letter to John Adams are cited. Epicurus’s Letter to Pythocles, Section 86, introducing the method of multiple explanations for celestial phenomena, is read in full and connected to Professor T.H.M. Gellar Goad’s article “Lucretius on the Size of the Sun” — which argues that “the sun is the size it appears to be” functions as an Epicurean shibboleth, not a blunder. Joshua closes with a passage from Giordano Bruno’s On the Infinite showing Lucretian influence. The episode concludes that “all sensations are true,” “death is nothing to us,” and “pleasure is the absence of pain” are all deliberately challenging constructions designed to make you think past the superficial.
Transcript
Section titled “Transcript”Cassius: Welcome to Episode 263 of Lucretius Today. This is a podcast dedicated to the poet Lucretius, who wrote On the Nature of Things, the most complete presentation of Epicurean philosophy left to us from the ancient world. Each week we walk you through the Epicurean texts and we discuss how Epicurean philosophy can apply to you today. If you find the Epicurean worldview attractive, we invite you to join us in the study of Epicurus at EpicureanFriends.com, where we discuss this and all of our podcast episodes.
Today we’re turning our attention to another of the key doctrines of Epicurus. Last week in our series, we discussed the question of whether knowledge is possible, and this week we’re going to discuss the related issue that is encapsulated in the phrase “all sensations are true.” While there are many variations of the statement about how important it is to realize that the sensations are true, the phrase “all sensations are true” is more of a good way to remember the doctrine rather than an exact quotation from one of Epicurus’s letters or from the Principal Doctrines.
As we discussed regarding knowledge itself, it was critical to Epicurus to take a position on the fact that certain things in life — especially important issues such as the existence of supernatural gods or the existence of life after death — it was important for Epicurus to take a firm position on the truth and falsity of contentions about those issues. As we know from Lucretius and from Epicurus himself, the Epicureans were reacting against aspects of Pyrrho, aspects of Socrates, even aspects of Aristotle in which the contention had been advanced that truth was impossible to determine through the senses. And since Epicurus was taking the position that knowledge is possible, he had to ground it on a faculty that is available to all of us as humans and given to us by nature. That’s where Epicurus grounded his theory of truth — on the sensations.
Of course, if the sensations were found to be unreliable, that would not be an adequate foundation for truth, and so Epicurus turned his attention to the question of whether sensations are true or not. Because that was the general objection of people in his day and people today as well: that the sensations can’t be trusted, the sensations are subject to illusions and all sorts of distortions that prevent them from being a reliable basis for knowledge.
The answer to that challenge that Epicurus focuses on is to observe that the senses themselves are not evaluating the data that they receive. The sensations are simply reporting data, and the true-or-false evaluation of that data is not a part of the senses themselves but a function of the mind. Therefore, truth and falsehood are functions of the brain — of the mind — and when we come to a conclusion that proves not to be consistent with future sensations, the fault is not attributable to the senses but is rather attributable to the reasoning process within the mind.
Lucretius in Book Four, at line 478, said: “You will find that the concept of the true is begotten first from the senses, and that the senses cannot be gainsaid. For something must be found with a greater surety which can of its own authority refute the false by the true. What must be held to be of greater surety than sense? Will reason, sprung from false sensation, avail to speak against the senses, when it is wholly sprung from the senses? For unless they are true, all reason too becomes false.”
We can also observe that this doctrine is embedded in the Principal Doctrines very deeply, as well as the letters of Epicurus. Principal Doctrine 2 — which is really focused on death — says that “death is nothing to us, for that which is dissolved is without sensation, and that which lacks sensation is nothing to us,” meaning that sensation is the foundation of everything that is relevant to us, and if we don’t sense it, then that issue is not relevant to us and is essentially nothing to us.
Principal Doctrine 22 says: “We must consider both the real purpose and all the evidence of direct perception to which we always refer the conclusions of opinion. Otherwise all will be full of doubt and confusion.” And so the evidence of direct perception is a reference to the senses, and to those senses we always refer the conclusions of opinion.
And then Principal Doctrine 23 says: “If you fight against all sensations, you will have no standard by which to judge even those of them which you say are false.”
Principal Doctrine 24 makes a similar point in explaining how you cannot reject any sensation, because each sensation is entitled to the same credit. And so you have to accept that the senses can differ from observation to observation, and it is your job — in your mind — to evaluate why they are differing and incorporate all of the data into a coherent conclusion. According to Principal Doctrine 24, if you don’t keep separate in your mind opinions which you don’t really have enough data to be sure of from those that you do have enough data to be sure of, then you will never be able to escape doubt and never be able to arrive at a firm conclusion as to what is right and what is wrong.
The same thing is discussed at the Letter to Herodotus, Section 38, where Epicurus talks about images and beliefs that are formed on images, and he says: “For not one of these beliefs is contradicted by our sensations if one looks to see in what way sensation will bring us clear visions from external objects.” And in Section 52 of the Letter to Herodotus, Epicurus said: “Therefore we must do our best to keep this doctrine in mind, in order that on the one hand the standards of judgment dependent on the clear visions may not be undermined, and on the other error may not be as firmly established as truth so as to throw all into confusion.”
So Epicurus is repeatedly telling us to evaluate how the sensations are operating — evaluate the difference between what the sensations are doing versus what the reasoning mind is doing. And when you put all that together, there is no reason to take a blanket position that: “Well, the senses are subject to illusions, the senses are always subject to error, and therefore we cannot rely on the senses and we must look for something instead of sensation to get us to any kind of truth or reality that we can ever hope to find.”
So in summary, what Epicurus was dealing with can be thought of as a response to challenges to the senses such as were advanced by Plato in his famous cave analogy — the idea that the sensations are not able to see the real truth but only pick up at best flickering shadows on a wall, that the senses therefore must be abandoned and you must come out of the cave into a new light that Plato is going to show you through logic and reason, which is not the same as your senses, which are fatally flawed, fatally unreliable, and ultimately something that has to be discarded. Epicurus is taking the opposite position. He is saying: no, you’re wrong, Plato — you’re wrong, everybody who says the sensations cannot be relied on. Once you analyze the sensations properly, you’ll see they not only can be relied on, but they must be relied on, because they provide all of the data that your reason is going to be working with. And if you take the position that the sensations are unreliable, then you necessarily will result in unreliable reasoning, because that’s the starting point for every bit of reasoning.
Joshua: Last week we did an episode on whether knowledge is possible, and there’s bound to be some overlap between these two questions — “are the senses reliable?” and “is knowledge possible?” — especially since Lucretius said there, as you quoted, that the senses are in many ways the foundation of our knowledge. I saw a comment on Reddit the other day — I don’t even remember the topic — but the comment was something like: “How can you pretend to have it figured out when you can only see 35 ten-thousandths of the electromagnetic spectrum? The spectrum that we call visible light is 0.0035% of the total electromagnetic spectrum.” And so the question is: how can you pretend to have any certainty about anything if you are so blinded compared to the amount of information that is available?
When we’re dealing with the question of the truth or falsity of the senses, nowhere at any point are we making the claim — nowhere at any point is Epicurus making the claim — that the senses are omniscient. We don’t see everything; that’s not part of the argument here. It’s estimated that there are maybe 5,000 stars visible to the naked eye from any point on the surface of the earth. It’s estimated that there are 100 billion stars in the Milky Way galaxy alone. Again, our senses are not omniscient — we don’t see everything there is to see, we don’t hear everything there is to hear.
I always thought it was interesting that Marconi, the guy who invented radio technology, had the strange belief that sounds never fully dissipate — they just get quieter and quieter and quieter as time goes on — and he seemed to think that if you knew how to measure it and you knew where to look, you could, for example, today tune into the voice of Jesus delivering the Sermon on the Mount. This is not our best understanding of how sound works. Even with instruments that extend our senses vastly better than our senses are in their native state, and vastly better than the extensions we’ve already made to our senses using the instruments that we have now, we’re never going to hear, see, or smell everything. So that’s just not part of the claim that’s being made here. I think what Epicurus is saying is that the information that we do get from our senses — limited though it is — is going to be reliable. We’re not pretending to omniscience here; that would be my main point on that.
Cassius: Yeah, Joshua, you’ve pointed out one of the key issues here, which is that there are limitations to the senses, there are distortions that occur, there are all sorts of illusions that occur as Lucretius goes into in great detail. But just as you’re saying that you only see 5,000 stars out of basically an unlimited number of stars if you go out far enough — the knowledge that your senses are limited, the knowledge that you are subject to distortions — the way to deal with those distortions and come up with reliable opinions is to take those distortions and those limitations into account. And you cannot take them into account if you don’t realize that they are there. So the proper processing of the data that comes from the senses is going to take into account the limitations to the senses, and you will use that knowledge of the limitations to make multiple observations and make observations from different directions and test your observations against the observations that other people are making and make them over long periods of time. And taking into account those limitations, you can correlate the data in your mind and come to a reliable opinion.
But the kind of dark aspect of this that people have difficulty grasping is that nowhere along the line are you taking any of these sensations and saying, “well, that sensation was false” or “that particular sensation was true.” The sensation is what it is. And when you look up in the sky and you see 5,000 stars instead of an unlimited number, the way to process that is going to be to consider the distance that’s involved and correlate all that data together, at which point you’ll realize that the distance will affect what your eyes are reporting to you. When you include the distance in your calculation, you can come to an opinion that you can have confidence in.
Joshua: Yeah, I think that’s right, Cassius. The ancient Epicureans apparently referred to Epicurus’s book on the canon of sensations, feelings, and prolepses as the “celestial volume” — the book that fell from heaven — being compared here to the Palladium, the wooden statue that fell from heaven and was the centerpiece of Trojan religious life in Homer’s stories. Lucretius refers to “divine touch.” This grandiose language is appropriate because this is how we interface with nature. This is how we connect with each other as humans. Without our senses, if we’re relying purely on, for example, a priori knowledge and we have no senses, we are blind to the world that we’re living in and we’re blind to the past and we’re blind to any predictions we can make about the future, because we have no real information to work with — we’re just deriving deductive conclusions from a priori logic and there’s no real foundation to that.
In Epicureanism, the canon is the foundation and the senses are sort of pride of place. I don’t want to overemphasize the senses and downplay the feelings and the prolepses, but this is how we interface with the world around us. When Lucretius refers to touch as divine, this is not engaging in religion-building or mythology — this is drawing our attention to the importance of these faculties. I don’t think that should be overlooked.
Cassius: Yes, Josh, I would completely agree, especially with your citation to the canon falling from heaven. Now, this is a philosophical point but it is so critical to coming to a proper philosophy, because it is fundamental to Pyrrhonism, Socrates, these other philosophies that the senses cannot be relied on — something else is necessary, whether it be divine revelation or rationalism of some kind. Something else is required in order to establish truth beyond the senses, and to the extent you should separate yourself from the senses because the senses are so much by nature unreliable that they’re essentially lying to you, you’ve got to get around the senses in order to determine what is the truth of reality.
So it’s really important then to understand that the phrase “all sensations are true” cannot be read superficially. You have to think about what is meant by “all sensations being true,” but then once you do grasp the point, I think there is a legitimate comparison to having something drop down from heaven, because the blinders of doubting the senses can fall away from your eyes when you realize that truth and error is not in the senses — truth and error is somewhere else — and then you go attack that somewhere else, but you don’t throw away the senses because you think that they’re lying to you.
This is a subject that Norman DeWitt talks about at length, not only in his book but in a separate article that he wrote entitled “All Sensations Are True.” Here’s a statement from the beginning of that article that I think is helpful in understanding how we can analyze this problem.
DeWitt says: “The aim of this article is to show reasons for believing that the statement in the heading — which is ‘all sensations are true’ — is false as usually understood. It is absurd. The documentation is deficient, misleading, and from prejudicial sources. Advocates of its validity go beyond their authorities. It is inconsistent with Epicurus’s theory of perception, with his terminology, with his account of vision, with his classifications, with his treatment of the criteria in his Principal Doctrines, with his account of heavenly phenomena in the Letter to Pythocles, and with his recommendations to students. Ancient proofs of it are polemical sophistry. Modern misinterpretations have arisen from ambiguity of the Greek word for ‘truth,’ which has three meanings in Epicureanism: number one, real or self-existent; number two, relatively true; or number three, absolutely true. Sensations have been confused with judgments.”
Now that’s a very pithy statement of all the different objections that DeWitt is going to go on to explain. But his point is that as generally understood, the statement “all sensations are true” is absurd. We all know why it’s absurd — we’ve all been there and heard the criticism that the sensations can’t be relied on, and so when somebody stands up out of the philosophical crowd and says “not only are the sensations reliable, but in fact all sensations are true” — that is something that, unless you understand the meaning behind it, is absurd on its face.
Now obviously from the position of people who think that Epicurus has a lot of useful things to say, we don’t take the position that Epicurus was making absurd statements. The statements that Epicurus did make about the reliability of the sensations have to be understood in a way that is not absurd, in a way that is not inconsistent with his other theories and his other presentations of the way the mind operates.
DeWitt gives an example. He says: “The zeal of Epicurus’s detractors is sufficient to place the impartial student keenly on his guard. John Mason wrote: ‘The first principle of the Epicurean theory of knowledge is that all sensations are of themselves reliable.’” DeWitt says: “This goes beyond all authority. Epicurus undoubtedly did say that all sensations were true, but this is not to say that they are all reliable. Epicurus assumed that their reliability varied according to distances. Neither was it right to speak here of a ‘first principle’ — there can be no comparison among essentials. The canon was based upon three things: the sensations, the feelings, and the general concepts. These form a tripod, and one leg of a tripod cannot be more important than another.”
So in that citation, DeWitt is explaining that the word “true” does not mean the same thing as the word “reliable.” The sensations report data to you truly in the sense of honestly, but that does not mean that they are reliable in the sense of telling you what things are. Reporting reliability means that you’re going to be able to form an opinion about what is true that you can rely on as you confront new situations. That’s not what the senses do. Senses never give you an opinion. That’s the function of the mind, and the processing of data to come to opinions takes place there and not in the senses.
It’s worth noting that Epicurus’s position on the truth of the senses is not without precedent, and that Aristotle himself said some things that are very close to this. In Philip and Estelle DeLacy’s Philodemus: On Methods of Inference, DeLacy says: “Aristotle’s attitude towards empirical method is more favorable than Plato’s, for though Aristotle denies that empirical observation alone is adequate for knowledge, yet he does regard perception as the starting point of all knowledge. In one passage he says that each sense organ has its distinctive objects of perception, and in regard to these objects it never errs.” That is on page 126 of the DeLacy book. And that’s a very similar position, as far as it goes, to what Epicurus was saying: that in regard to their objects — the tongue as to taste, the ear as to hearing, the eyes as to seeing — they never err in the sense of providing you a false opinion. And that is because they are not providing you opinions at all. They are providing you data on which your mind is forming opinions.
Joshua: Yeah, and in Section 71 of the first book of Cicero’s On Ends, he ends his monologue in defense of Epicurean ethics principally by saying this: “Wherefore if the doctrines I’ve stated are more dazzling and luminous than the sun itself, if they are drafts drawn from nature’s spring, if our whole argument establishes its credit entirely by an appeal to our senses — that is to say, to witnesses who are untainted and unblemished — if speechless babes and even silent beasts almost cry out that with nature for our governor and guide there is no good fortune but pleasure, no adverse fortune but pain, and their verdict upon these matters is neither perverted nor tainted — are we not bound to entertain the greatest gratitude for the man who, lending his ear to this voice of nature as I may call it, grasped it in so strong and serious a spirit that he guided all thoroughly sober-minded men into the track of a peaceful, quiet, restful, and happy life?”
This to me seems like par for the course, Cassius — referring to the senses as witnesses who are untainted and unblemished, neither perverted nor tainted. As you say, it’s just data. This is just data streaming in. The error comes from the judgment of the mind that is layered on top of this data as it’s coming in, on the time we spend reflecting on the data. If we’re reflecting incorrectly about the data — but the data itself is just a witness in court, untainted and unblemished. This is Cicero and Torquatus. Cicero is quite good when he wants to be in defense of Epicureanism, and I think that’s a very good paragraph.
Cassius: It is, and it’s the summation — the closing argument — of Torquatus’s complete defense of Epicurean ethics. He spent page after page talking about virtue and the question of whether the goal of life is virtue versus pleasure or not. But in the end he comes back to this as his closing argument: that everything that Epicurus has said is reasonable and reliable because it’s based on the senses, and the senses are the things that nature gives us to judge things by — and it’s not based on some arbitrary notion or idea that some philosopher has made up on his own and cannot connect back to nature.
In the book I just cited from Philip DeLacy, DeLacy talked about Aristotle a little further, and this is a good illustration of where Epicurus is correcting a problem that even Aristotle — who was recognizing the senses as important — did not correct. DeLacy said: “In spite of such statements as these, Aristotle does not formulate his own scientific method in purely empirical terms. He says that science requires the use of both reason and perception, and only once does he indicate that perception is the ultimate test. In the absence of rational explanation, he refers to an empirical generalization merely as a ‘probable conjecture.’ Aristotle regards empiricism as inadequate because he believes that observation can never give necessary connections between objects. In the absence of causal knowledge, the empirical scientist must base his knowledge on a study of signs, and inferences from signs are not reliable except in cases where inferences may be converted into valid syllogisms.”
The really important part of that is that last aspect: Aristotle and these other philosophers — including the Stoics, Plato, Socrates, and so forth — they don’t believe that observation through the senses can ever tell you necessarily what is going on. There’s no way to bridge that gap between the data you’re receiving through your senses and a reliable way of predicting other things that are going to happen to you. Inferences from the senses are not reliable except in cases where those inferences can be converted into syllogisms — these logical constructions that they, including Aristotle, take to be the real source of truth. The senses and the conclusions you reach based on the senses alone can never be true according to Aristotle, again unless you can place it into the form of a syllogism, and that’s near the heart of what this argument is all about.
In that, Epicurus’s form of reasoning is a practical one that’s always looking back to the senses as the test of what is true and false. Because your opinion is confirmed to be true or false not by some idea that you have reached in the past, but by checking the opinion against the current data that you’re receiving through the senses. You’re not checking your opinions against other opinions ad infinitum without ever coming back to the reality of the senses.
Epicurus is saying that yes, you have deductive logic, yes, we build our physics and our ideas of atoms and void on deductive logic — but in the end we check those deductions against the senses, and if we can’t validate our opinions against the senses, then those opinions aren’t worth having, because the senses are the source of all that is real to us.
Now at this point in our discussion of these key doctrines, I usually try to throw in a section about whether the question of whether sensations are true still matters today — whether this is an issue that’s been resolved and fit only for the dustbin of philosophical history, or whether it’s still a current problem. And again, like the rest of key aspects of Epicurean philosophy, this issue can sound academic, and it certainly is when you dig into the details of different philosophers arguing against each other. But ultimately it’s as real as the question of whether you’re going to trust your own eyes and ears and your own experience, or whether you’re going to listen to divine revelation, or whether you’re going to listen to people talking to spirits and other assertions that you can’t validate and that you can’t experience for yourself.
Epicurus is pointing out that our senses are all we have to come into contact with the world, and everything we do in terms of pleasure and pain comes to us ultimately through our observations — through the senses. So it’s really important to be able to stand up to the challenge of those who say that there has got to be some higher law, some higher method of understanding, because we certainly can’t rely on our senses because they lead us astray — that far from being instruments of understanding truth, our senses are sources of temptation that lead us away from what is important in life, which is the spirit, the soul, the mind. And all of these perspectives that seek to divorce the mind from the senses, Epicurus is to say: not only is that simply false, but everything we have — all the operations of our mind, all the operations of our spirit — are ultimately grounded in and have to rely on the senses. And so unless we have confidence in our senses, we can certainly not have confidence in anything else in our lives.
In addition, Norman DeWitt on page 213 of his book says: “The status of the volitional mind, which alone is truly rational, is that of a judge presiding in court. Litigants are truth and error. The role of the sensations, anticipations, and feelings is that of witnesses. The judge who becomes his office rejects no evidence that is pertinent. He distinguishes between mere opinion and knowledge, between the idea that awaits confirmation by additional evidence and that which is already certain, between the immediate dependable sensation and the deceptive distant view, between false pleasures and wholesome pleasures, and between true and false concepts of abstract truth. If the mind falls short of performing these judicial functions, the conflict in the soul will be prolonged and no satisfying decision between truth and error will be attainable.” This is the gist of Principal Doctrine 24, and I do think this analogy of the sensations, anticipations, and feelings being witnesses is a very, very good one.
Most of us are familiar with the way that proceedings take place in a courtroom, and that in our American system we let the jury be the judge of the facts. The jury is going to hear all of the evidence from every witness, whether the witness is totally honest or the worst fraud ever to walk the face of the earth. In our legal system, witnesses are allowed to testify to what they observe, and it’s the function of the jury to determine whether what has been testified to is true to the facts and can be relied upon or not.
Now the judge has a role in deciding what evidence is allowed in, but the judge doesn’t keep out evidence just because he disagrees with that evidence. He has rules of processing of evidence which he’s going to tell the jury about. If you’ve ever been in court, the judge is going to tell you: “Think about whether the witness had an opportunity to observe all of the facts or not, how far away they were” — all sorts of considerations that factor into whether the witness really is a good witness or not, whether the witness really saw what happened or only saw a part of the proceedings. All of those factors — the judge will tell the jury — think about these factors when you listen to what the witnesses say. But you are the judges of the facts and you can accept or reject any or all of the testimony of a witness who gets on the witness stand.
The point that DeWitt is making is that the sensations, anticipations, and feelings will report whatever it is that comes to their attention. It’s up to the jury — the mind — to decide whether what has come to their attention is something that you can build upon to form a true opinion or not. Lots of things come to the attention of lots of witnesses, but only certain aspects of what is observed really end up being usable to form a full picture of the truth. That function of sifting the data, sifting the information provided by the witnesses, is the job of the jury using the procedures that the judge gives to the jury to form its final verdict.
Epicurus is saying that the mind is the jury and that the senses are the only witnesses we have on which to decide what is true and what is false. This shifts the burden of the analysis from saying “the senses aren’t reliable, let’s just throw them out” to the truth and the reality of the situation, which is that the senses are all the witnesses we’re ever going to have. It’s our job — using proper reasoning procedures — to take that information from the witnesses and turn it into an opinion that we can be confident of. And coming to an opinion that we can be confident of does not start with throwing out all the witnesses, does not start with discrediting all the witnesses and thinking that we can’t believe them at the very beginning.
Coming to an opinion that we can be confident of is very similar to what the jury is doing in assembling the data into a coherent picture of the truth — which is not to say that juries never get cases wrong, which is not to say that human judgment is omniscient or can never err, but it is to say that this is all we have. And if we go looking for supernatural answers, if we go looking for answers in mathematics or some other source that is beyond the only witnesses we have, then we have forever barred ourselves from making use of the only testimony that nature gives to us.
Joshua: Yeah, Cassius, I think this is such a strong analogy because it puts distance between the mode of receiving information and the judgment or processing that we perform working with that information. And I know we quoted last week from Thomas Jefferson’s letter to John Adams on skepticism because it was relevant last week as well, but Jefferson does a very good job here of feeling out that difference between the stream of information coming in and the judgment that we add to it. And this is what he says: “I am obliged to recur ultimately to my habitual: I feel, therefore I exist.” He says, “I feel” — the information streams in — and then he says “therefore I exist,” based on the information, based on the witness’s testimony. He adds this judgment and keeps going. He says: “I feel bodies which are not myself, therefore there are other existences. Then I call them matter. I feel them changing place. This gives me motion. Where there is an absence of matter, I call it void, or nothing, or immaterial space. On the basis of sensation of matter and motion, we may erect the fabric of all the certainties we can have or need.”
I think Jefferson does a very good job there of noticing that difference and making it very clear that that difference is there — the difference between the sensation and the judgment that operates on the sensation. We’ve said it many times in this series: most of what we’re talking about, the stuff all locks together; it’s so foundational to all of the rest of Epicurean philosophy it almost can’t help but lock together. This particular passage from Thomas Jefferson’s letter to John Adams really gets the key point really well — Jefferson in that letter is dealing with clear sensations on which we can build really solid foundations and not have to doubt them.
Lucretius in Book Four starts to get into questions of illusions. Where does the illusion happen? Does it happen in nature before the light even hits our eyes — say, the refraction of the atmosphere has already created the illusion? Is it layered on by our judgment on top of the sensation? So he gives a number of examples here in Book Four.
Starting at around line 353 in Book Four, he says: “And when we see from far off the square towers of a town, it comes to pass for this cause that they often look round, because every angle from a distance is seen flattened, or rather it is not seen at all, and the blow from it passes away, nor does its stroke come home to our eyes. Because while the idols are being borne on through much air, the air by its frequent collisions constrains it to become blunted. When for this cause every angle alike has escaped our sense, it comes to pass that the structures of stone are worn away as though turned on the lathe. Yet they do not look like things which are really round to a near view, but a little resembling them as though in shadowy shape.”
Okay, there’s quite a lot to unpack there. You’re far away from a town, you see the tower — the tower is square, maybe you already know this because you’ve been to that town and you’ve seen the tower close up — but from the distance that you’re seeing it now, it looks round. And this poses an interesting question to what we’ve been talking about all day. If “all sensations are true,” why doesn’t the square tower look square from far away? Are the senses lying about the tower? That’s the question that Lucretius is dealing with. He has an explanation based on the distance and the amount of air that the image has to pass through to get to our eyes. And he makes the further point that the square tower which looks round from far away does not look like things which are really round to a near view.
So this is one way to check the senses — the square tower looks round from far away because it all gets kind of flattened, but a tower that is genuinely round when seen from close up looks different from a tower that is square and merely looks round when seen from a distance. Now of course with the tower, you can always get closer to it and update your information. But that doesn’t save the problem — this would appear to violate the idea that all sensations are true. But if we go back again, Cassius, to the analogy of the senses not reporting everything — they’re limited in scope and they’re merely reporting the information without adding a layer of judgment onto it, that layer of judgment happens in the mind — I think with that consideration we can help understand this issue a little bit better. What is your take, Cassius, on the square tower that looks round from far away?
Cassius: Well, with the square tower versus round tower example, I think that’s just one among many — such as the colonnade that appears to converge, or the oar that appears to be bent in the water — and what they are doing is providing a demonstration that’s easy to understand that there’s something going on here that has to be reconciled. We know the oar is not bent when we pull it out of the water. We know that the columns in the colonnade do not really converge to a single point at a distance. And we know that the tower is either square or it’s round — it’s certainly not both. There’s an apparent contradiction between what we’re seeing at one time versus what we’re seeing at another time, and that’s where everything comes down to the critical question: do those inconsistencies cause us to abandon our confidence in the senses, or can we explain the inconsistencies and keep our confidence in the senses?
That’s where Lucretius says specifically that if you can’t explain the contradiction between various observations, still it’s better for you simply to accept that you don’t understand why they’re reporting differently than it is for you to jump to the conclusion that “oh my gosh, the senses are not reliable, I can never rely on them at any moment to do anything for me.” That’s the problem that’s being put in our face by the square tower analogy and all of these other examples.
Joshua: And of course we have a solution to this that they didn’t have in the ancient world: when you put a piece of wood into water and the image refracts and the wood — which you know to be straight — appears to be bent, you can take a photograph of that, and you know that the camera cannot add judgment to that image. The camera cannot add judgment to the light that is streaming into it. The resulting photograph can be tampered with, but the camera is just taking a snapshot of the light that is coming into its lens in that moment. And so by analogy we can say, well, our eyes are doing the same thing — we’re just taking what exists in nature and it’s just coming into the eyes. It’s not that the judgment faculty of the mind is adding the bend to the wood when it’s in the water. This is what the wood looks like when it’s submerged in water, because of what water does to the image as it’s coming toward our eyes.
Cassius: It’s difficult to place these observations into words, but that’s because to a significant degree, by the time you start expressing something in words, the mind has already begun that process. The process of assigning a word to an observation is a mental faculty that’s not being performed in your eyes. Neither the camera nor your eyes is translating the light that comes into it into a set of words and sentences that have opinions and conclusions within them. It becomes very difficult to talk about it because by assigning a word to what we’re discussing, the mind is processing the data. It’s difficult to say whether what the eyes are taking in is light and dark, or shape, or sharpness, or color — by the time you assign a word to it, you’re describing a reasoning, deductive process. That’s where Epicurus is pointing out that the eyes don’t do that. The eyes are simply relaying data to your mind and to your brain, where that is being assembled into words and conclusions and opinions.
Joshua: Yep. Another good example — here at line 400, Lucretius says: “When children have seized turning around themselves, so sure does it come to appear to them that the halls are turning about and the pillars racing round, that scarcely now can they believe that the whole roof is not threatening to fall in upon them.” Well, we know that the roof is not going to fall in, and the pillars are not spinning around in circles, right? Nor are the eyes sloshing around in their sockets after you stop moving. What’s happening is the data is coming in through the eyes, and the brain is comparing that information to a pocket of fluid in your ears which controls your sense of balance, and it’s using the information that it gets from both of them and combining it to provide the output of “it looks like everything is moving” — but that judgment is happening in the mind. It’s not in the sensation itself.
Cassius: Joshua, there’s a tremendous amount of detail that we are going to be linking to in today’s show notes where people can go into the commentators, they can go into the original text, and they can see the details of what we are talking about. What probably makes the most sense for us to do as we begin to conclude today’s episode is to really bring home the ultimate reason we are discussing this — and that is that the position that “all sensations are true” is associated with Epicurean philosophy in a way that is seen to be a great discredit to Epicurus by most people. They hear the statement “all sensations are true,” and normal people think that means that everything that we think we see, we think we hear, we think we touch — everything that comes to our attention that way is true — that the mirage that we think we see in the desert means that there really is a pond or lake of water over in that direction.
And the normal person who knows that illusions are an everyday part of human life hears “all sensations are true” and immediately jumps to the conclusion that this is Epicurus being an idiot, this is Epicurus being perverse, this is one of those typical philosophers who goes off in some direction that makes no sense and that causes us to abandon philosophy and take up religion or simply nihilism or nothing at all.
And the point that we have to make clear in discussing “all sensations are true” is that that obviously is not Epicurus’s point. Philosophy means wisdom in the approach of difficult questions, and to say that illusions never occur would be absurd. We know it, and Epicurus knew it too. Lucretius knew it too, and all you have to do is read Book Four or the other Epicurean texts to see that they were not idiots. They were perfectly aware of the problems of illusions and the attacks that are made on the senses by the other philosophers.
Just as in many aspects of Epicurean philosophy, the important thing to do is to look beyond the superficial interpretation and think about what Epicurus is really saying. One of the other examples of Epicurus’s approach that is often held up to ridicule — where he’s accused of blundering — is the position that Epicurus said that the sun is the size that it appears to be. Now even in Epicurus’s day, anybody with any common sense knows by looking at the sun in the sky as it sets, in comparison to mountains and buildings and other things that you know in the distance are extremely large, that the sun is not one foot in diameter. We can infer that from the evidence available to us even without modern science, and so could Epicurus.
So why then would Epicurus say the sun is the size it appears to be? Why would he say “all sensations are true” when obviously the superficial constructions of those statements don’t make sense and even an idiot can see that there’s an issue there?
For that part of this discussion, there is an article entitled “Lucretius on the Size of the Sun” by Professor T.H.M. Gellar Goad that we’ll also link to in the show notes. And the point that he raises there I think is probably where we focus our conclusion for this discussion today. Professor Gellar Goad construes Epicurus’s position in these areas as a didactic challenge — or a shibboleth, if you will — a way of expressing a point to challenge the existing orthodox viewpoint and to challenge you to look behind and underneath this commonly held view that the sensations are unreliable. What better way to make you focus on that than to say not only are they not unreliable, they’re true — and to expect the listener to think about what is being said and to think about the multiple meanings of the word “true.”
Professor Gellar Goad says this in his article: “In closing, I argue that the size of the sun is an Epicurean shibboleth. In Epicurus, in Lucretius, and in Demetrius we see the same formulation repeated with progressive elaborations that do not fully clarify the basic precept. The persistence of Epicureans in this formulation is not so much the result of reflexive dogma or pseudo-intellectual obscurantism as it is a passphrase or a litmus test. Think like an Epicurean and you will figure out that the sun’s appearance and the sun itself are two related but distinct things with two different sizes, that you must keep the infallible data of the senses — tactile as well as visual — in proper perspective when making judgments about your perception, and that the available data is insufficient to estimate the sun’s magnitude to an acceptable degree of confidence. Think that Epicureans believe the sun’s diameter is a foot, that they are absurd, and you have exposed yourself as un-Epicurean. The first-century AD Stoic Cleomedes, who as Asmis points out nowhere takes account of the Epicurean principle of multiple explanations, likewise fails this test when he mocks Epicurus’s position on the size of the sun. Thinking like an Epicurean, rather than figuring out the actual size of the sun, is, I suggest, the point of the Lucretian passage on the size of the sun, as it is indeed the fundamental point of Epicurean natural philosophy generally. Precise measurement of the sun’s size is not what is at issue for the Epicureans, and so proof of scientific error does not vitiate Epicurus’s moral philosophy.”
“The Epicureans pushed back so fiercely against their opponents’ mischaracterizations of Epicurus’s position because of the underlying epistemological and phenomenological principles. It does not matter to Epicurean ethics or to ataraxia whether the size of the sun is known. After all, the Epicureans did not need to affix a certain size to the sun to accomplish their core epistemological objective: to remove anxiety about divine control over cosmological phenomena. What matters, and the underlying reason for this Epicurean shibboleth, is a readiness to use careful reasoning and good judgment to embrace uncertainty about the nature of things without succumbing to anxiety-inducing fear of death.”
Now that’s the end of the section I’m quoting there. But that last sentence is what I would emphasize: that the reason for saying “all sensations are true,” the reason for saying that the size of the sun is as it appears to be, is that what’s important in life is to be able to use careful reasoning and good judgment to embrace the information that nature makes available to us without succumbing to the drumbeat of these other philosophers who say that the senses and nature are all totally lying to you about everything that’s important. And if you’ll simply come to them and listen to their god, listen to their rationalizations about logic, they can tell you what’s really true — but in order to get to that, you have to abandon what nature has given you and stop relying on the senses. That’s really what’s at stake and behind everything we’re discussing here. Illusions don’t invalidate the senses. The senses are all we have, all that nature gave us for this purpose. And not only do we not abandon them — we double down on our reliance on them.
Joshua: Epicurus expands on all of these points in his Letter to Pythocles, in which he deals with what he calls atmospheric or celestial phenomena. But as we discussed, Cassius, when we went through this text presumably years ago now on this podcast — this is much more a text on how to think. That’s really what this is about. This is Epicurus saying “I’m going to teach you how to think,” and when you learn that, you’ll be able to understand not just celestial and atmospheric phenomena but all other kinds of phenomena as well.
And so what he comes up with in the Letter to Pythocles is a method of multiple explanations for a given phenomenon. And this is his description of that, starting in Section 86 of the text. He says: “We must not try to force an impossible explanation nor employ a method of inquiry like our reasoning either about the modes of life or with respect to the solution of other physical problems — witness such propositions as that the universe consists of bodies and the intangible, or that the elements are indivisible and all such statements — in circumstances where there is only one explanation which harmonizes with phenomena. For this is not so with the things above us: they admit of more than one cause of coming into being and more than one account of their nature which harmonizes with our sensations. For we must not conduct scientific investigation by means of empty assumptions and arbitrary principles, but follow the lead of phenomena. For our life has not now any place for irrational belief and groundless imaginings, but we must live free from trouble.”
And we get into the meat of the question now when he says: “Now all goes on without disturbance as far as regards each of those things which may be explained in several ways, so as to harmonize with what we perceive, when one admits — as we are bound to do — probable theories about them. But when one accepts one theory and rejects another which harmonizes as well with the phenomena, it is obvious that he altogether leaves the path of scientific inquiry and has recourse to myth. Now we can obtain indications of what happens above from some of the phenomena on earth, for we can observe how they come to pass, though we cannot observe the phenomena in the sky, for they may be produced in several ways.”
And he finishes by saying: “Yet we must never desert the appearance of each of these phenomena, and further, as regards what is associated with it, must distinguish those things whose production in several ways is not contradicted by phenomena on earth.”
The problem at the heart of this is: things that are close to us here on earth we can witness with our senses up close, we can look at them at various angles, we can compare them with other things on earth that we’re familiar with. When it comes to the things in the heavens, even if the Greeks did have lenses, this probably wasn’t a widespread technology that everyone would have had access to. Epicurus is talking to people who have never looked through a lens in their life. So when you’re dealing with things in the sky, you don’t have the luxury that you have on earth to get up close to something and see it from different angles. You are at a stuck distance from the phenomena that you were observing. And so it would be rash to come to just one conclusion about that phenomenon when there are multiple explanations that — as he says here — harmonize with that phenomenon.
So this is where we get into the method of multiple explanations. He contrasts this with what he calls the method of the single cause: people who get attached to one cause and stick to it, never admitting that they might be wrong about that. This does bear some similarities with how we proceed in modern science — you witness a phenomenon, you come up with a series of possible explanations for it, and then you test them rigorously. Now Epicurus can’t test the phenomena of the sky rigorously, and to be honest, the Greeks didn’t really go down the path of rigorous testing on this stuff anyway. Instead, he has to stay with the multiple hypotheses, he has to stay with the explanations, and not arbitrarily rule them out in favor of just one explanation when all of them could be used to explain the phenomenon and still follow the rules about what we know about nature. And like he says here: “Our life has not now any place for irrational belief and groundless imaginings, but we must live free from trouble.” And when it comes to, for example, the size of the sun — when it comes to other phenomena in the heavens — particularly in the fourth and third centuries BC there’s no way really to get hugely better information about this stuff, and so you have to be able to accept a level of uncertainty rather than just clinging to one thing and pretending when really you don’t.
Cassius: Right, Joshua. I think that’s the important point. What Epicurus is saying in the Letter to Pythocles, as you just said, it’s a perfect extension of the analogy of the tower to distance, because it’s got a very clear distinction: you can walk up to the tower to distance and test whether it is square or round. You cannot physically get up into the heavens and look at the stars close enough to be sure of what it is you’re seeing. And so that goes right back to what Lucretius is saying in Book Four, around line 500, because in that situation you’re looking up at the stars and multiple things could be going on.
So what are you going to do when you can’t reduce the explanations for what you see to a single answer? This is exactly what Lucretius says, Book Four, line 500: “If reason is unable to unravel the cause why those things which close at hand are square are seen round at a distance, it is better through lack of reasoning to be at fault in accounting for the cause of either shape rather than to let things clearly seen slip abroad from your grasp and to assail the grounds of belief and to pluck up the whole foundation on which life and existence rest. Not only would all reasoning fall away — life itself too would collapse — unless you choose to trust the senses and avoid headlong spots and other things of this kind which must be shunned. Know then that all this is but an empty store of words which has been drawn up and arrayed against the senses.”
So that’s really the important point here: every hope that we have for constructing a happy life relies upon the senses being trustworthy, that the information we get is not deceptive and lying to us, and that we can construct the philosophy that gets us to a happy life.
I really do think that Professor Gellar Goad’s point is why these conclusions are constructed the way they are. “All sensations are true.” “The size of the sun is as it appears to be.” If you take the position that those statements are absurd and that Epicurus is an idiot, then you have shown yourself that you’re not thinking about what Epicurus is really saying. Once you think about his point, you begin to see that what Epicurus is calling you to do is to get behind the superficial interpretations of things that play into the hands of supernatural religion and play into the hands of false philosophy and cause you to doubt your own ability to live your life happily on a foundation that, as Jefferson said, is enough for all the certainties that you need in life in order to live.
That’s the way that “all sensations are true” should be construed — in a way that makes sense and is consistent with the rest of Epicurean philosophy. And so getting comfortable with phrases like “death is nothing to us,” or “pleasure is the absence of pain” — those constructions require thought and understanding, but when you do think about them, they make an awful lot of sense and justify continuing into the study of Epicurean philosophy to understand them even better. Why don’t we bring today’s episode to a conclusion at that point? Any final thoughts today, Joshua?
Joshua: Yeah. Giordano Bruno wrote a text On the Infinite, and he has an interesting passage from this which I think clearly shows the influence of Lucretius — one of his favorite authors — on his philosophy. He is not really an Epicurean, but he does often venture into the same realms, and this is one of the instances in which he does it. He says: “Such then is the heaven, the immense space, the bosom, the universal continent, the ethereal region through which everything flows and moves. There innumerable stars, heavens, globes, suns and earths are seen through the senses and the existence of infinite numbers is argued through reason. The immense and infinite universe is the composition that results from such a space and so many bodies comprised within that space.” In other words, what he’s saying is: even from our position on this meager earth that we’re standing on, looking out into the heavens, all of the things that we see out there — detecting them with our senses — are themselves evidence that reason uses to infer the existence of infinitely more of those bodies, those earths, those suns, those stars. And so this is a very Lucretian and Epicurean concept. I think he’s taking the senses as his starting place and then using the reasoning faculty of the mind to build upon that evidence and to come to a conclusion which is very similar, if not identical, to the conclusion that Lucretius and Epicurus came to about the infinity and eternity of the universe and the infinite number of other worlds that are in that universe. So again, it all comes back down to the senses as the primary mode of canonical information about the nature of the universe that we live in.
Cassius: Yes, it does come down to issues just like that, and that’s why it’s so important to focus on distinctive phrases such as “all sensations are true” so that we can deepen our understanding of Epicurus’s perspective. Epicurus was reputed not to have recommended the composition of poetry, and so Epicurus’s works aren’t preserved in the same way that Lucretius’s poem was preserved as something eloquently written. But as I think about it, I wonder if constructions such as “all sensations are true” and “death is nothing to us” and “pleasure is the absence of pain” weren’t used by Epicurus in a way similar to what Lucretius was doing in committing the philosophy to poetry. These are memorable constructions that are very easy to remember, but are also very challenging and superficially can be made to seem absurd. Very little in Epicurean philosophy can be made to sound more absurd than “pleasure is the absence of pain.”
But Epicurus is fond of constructions that are challenging like this because that’s what Epicurus is all about: educating people to understand the way of the world, the way of nature, and to see the way forward to a happy life — as opposed to giving in to outside oppression or nihilism or hopelessness that can come from failing to understand and think about the way things really are. So thinking about “all sensations are true” — getting comfortable with a construction like that will go a long way in understanding Epicurean philosophy better.
Okay, let’s close at that point today. As always, we invite you to drop by the Forum and let us know if you have any comments or questions about this or any of our other episodes. Thanks for being with us today. We’ll see you again soon. Bye.