Episode 032 - The Atoms Are Colorless, But The Implications of That Are Not
Date: 08/22/20
Link: https://www.epicureanfriends.com/thread/1655-episode-thirty-two-the-atoms-are-colorless-but-the-implications-are-not/
Summary
Section titled “Summary”Episode 032 returns to Book Two for a three-person panel (Cassius, Martin, Elaine — Charles is absent) examining Lucretius’s argument that the atoms are colorless. Martin reads the passage, which argues: atoms have never been seen, so no color can be attributed to them; a person born blind can understand bodies through touch without any color impression; every color we see can change, but the atoms cannot change without ceasing to exist — so color cannot be intrinsic to them; the colors of things arise from varying arrangements, positions, and motions of colorless atoms; and color cannot exist without light, as demonstrated by interference colors — the iridescent plumage of doves and the peacock’s tail, which change appearance as the angle of illumination changes. Martin finds the interference-color observation particularly impressive: Lucretius noticed these anomalous phenomena and correctly intuited that if apparent color changes with conditions alone, it cannot be a fundamental property of elementary particles.
The most philosophically significant passage is: “there necessarily must be something that remains immutable, lest all things should be utterly reduced to nothing.” Cassius, Martin, and Elaine conduct a careful three-way debate on this claim. All agree that Lucretius was right about indivisibility: particles appear to have a natural limit, and observations support the conclusion that matter is not infinitely divisible (electrons appear indivisible; physical reality shows defined, reproducible classes of particles). But Elaine firmly separates immutability from indivisibility — Lucretius went too far in asserting that elementary particles must be permanently unchanging. Modern physics shows that individual particles can be produced and destroyed; what persists is the class of particles, which is always reproducible under comparable conditions. Martin explains that while Lucretius’s specific models are mostly wrong by modern standards, they served their purpose: demonstrating that a complete account of natural phenomena requires no supernatural explanation.
Frances Wright’s Chapter 15 of A Few Days in Athens is read, on whether color can exist independent of matter (“to conceive of mind independent of matter is as if we should conceive of color independent of a substance colored”). All agree color cannot exist independently. Elaine distinguishes the quantifiable aspect of color (wavelength of light) from qualia — what it subjectively feels like to see red — and argues that our ability to mentally recall colors does not imply they exist independently, because the brain is simply reproducing the original perceptual processing. Aristotle and Theophrastus are identified as holding that color exists as an essence within an object (an Aristotelian intrinsic quality rather than a Platonic ideal form), and that is what Epicurus is objecting to. The episode closes with a discussion of whether color belongs to the category of “events/accidents” from Book One (like the Trojan War, an accident of a particular time and place) or to permanent properties. Martin argues color falls between: for ordinary paint it is a stable characteristic; for interference colors it is more accidental, varying with the angle of light. The broader lesson Cassius draws: there is a difference in the standard of analysis we apply to material things — where precise, objective statements are possible — versus the contextual, evaluative choices of life such as war, peace, riches, and liberty.
Transcript
Section titled “Transcript”Cassius: Welcome to Episode 32 of Lucretius Today. I am your host Cassius, and together with my panelists from the EpicureanFriends.com forum, we’ll walk you through the six books of Lucretius’ poem and discuss how Epicurean philosophy can apply to you today. Be aware that none of us are professional philosophers and everyone here is a self-taught Epicurean. 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. Today we’ll be discussing the implications of the Epicurean doctrine that the atoms are colorless. Let’s join the discussion with Martin reading today’s text.
Martin: Now come on, attend to the rules which I have found by a labor very delightful to myself. Lest you should think those bodies that appear white to your eyes are composed of white seeds, or such as show black are formed of black, or whatever color so ever a thing wears, you should conclude the cause of it to be that the seeds of which it is made are stained with the same color — for the principles of matter are void of all color, both like or unlike what appears upon the bodies they produce. If you should chance to think that the mind cannot possibly form an idea of seeds without color, you are under a strange mistake. For a person born blind, who never saw the light of the sun, yet discovers bodies by the touch, as if they had no manner of color belonging to them. So that seeds imbued with no color can offer themselves to our mind and be conceived by us. And besides, the things we touch in the dark night we distinguish without any regard to the color they may otherwise appear in.
That seeds may be void of color I have shown; I share no proof that they actually are so. Now every color may be changed one into another, but the principles of things will by no means admit of change. There necessarily must be something that remains immutable, lest all things should be utterly reduced to nothing — for whatsoever has changed and breaks the bounds of its first nature instantly dies and is no more what first it was. Be cautious therefore how you stain the seeds of things with color, lest all things should recur to nothing and be utterly destroyed.
Besides, though nature bestows no color upon seeds, yet they are endued with different figures, from which they form and vary the colors of every kind which show upon them. For it is of great concern what seeds unite with others, and what positions they are preserved in, and what motions they give and receive among themselves. And thus you may readily account why things that just before appeared black should suddenly look white — as you see when the rough winds enrage the waters, it grows white with foaming waves. So you may say of what commonly appears black to us: when the seeds of which it is formed are mingled and their order changed, when some new seeds are added and some old ones are removed, the direct consequence is that its color is changed and appears white. But if the water of the sea consisted essentially of blue particles, it could by no means change into a white color. Disturb the order of the seeds how you would, the principles that are blue would never pass into white. But if you say that the seeds which make the sea look of one uniform hue are stained with different colors as a perfect square — that is, one figure — is made up of separate bodies that are of several figures, it would follow that as we perfectly see the dissimilar figures which the square contains within it, so we might discover in the water of the sea, or in any other body of one simple color, the mix of different colors from which that simple color proceeds. Besides, the dissimilar figures that go to make up a square do by no means hinder that the surface of the body should appear square, but a mixed variety of colors would prevent that the surface of any body should appear of one fixed and uniform color. And then the very reason that would incline us sometimes to impute colors to seeds is by this means destroyed — for in this case white bodies are not produced from white, or black from black, but from seeds of various colors. Now white would much sooner proceed from seeds of no color at all than from such as are black or any other opposite color whatsoever.
Besides, since colors cannot appear without light, and since the seeds of things cannot appear in the light, you may then conclude that they are covered with no colors at all. For how can any color show itself in the dark, which changes even in the light itself as it is differently struck either with a direct or oblique ray of light? After this manner, the plumes of doves, which draw about their neck and are an ornament to it, show themselves in the sun. In one position they appear red like a fiery carbuncle; in another light the greenness of the emerald is mixed with the sky-blue. So likewise the tail of the peacock, all filled with light, changes its colors as the rays strike directly or obliquely upon it. Since therefore colors are produced only by the strokes of light, we cannot suppose that they can possibly exist without it.
Cassius: Thank you, Martin. So we’re back this week to discussing the characteristics of the atom, and today’s focus is on color — but it probably goes a lot deeper than what we might superficially think the issue is. Only one thing before I ask for comments: nobody has ever seen an atom before, and Epicurus is not saying that we can see atoms, and yet we’re discussing whether they have a color or not. So that is itself a question. What form of analysis are we using here? How do we approach something in terms of saying that it has a visible characteristic when we’re talking about something that’s invisible by nature? I want to hear what Martin says about this first.
Martin: What I’m impressed with is that he particularly pays attention to interference colors — that’s what he comes up with in the colors of these feathers — because they are produced in a different way than the regular color of a regularly painted object. Of course, he doesn’t know the difference in these colors, but he at least feels there’s some difference there. And he makes sense of it, then, by concluding that if the appearance of color can change with conditions alone, it cannot be a fundamental property of the elementary particles.
Cassius: Right, right. That’s fascinating to me that he noticed that. It does show you — so I think there’s a mix here: once again, reaching conclusions beyond what observations can strictly tell you, but right here at the end where he talks about the light, your observations can be very informing if you’re really paying attention. You realize things. That’s pretty cool.
Martin: And of course, from today’s models — where we know how color arises and how it comes — it just appears strange how this is formulated here. But nevertheless, it’s quite interesting that you really can draw somewhat partially valid conclusions from just thinking carefully about your observations. And if we try to think about how we could define a color for an elementary particle — we would need to expand the electromagnetic spectrum considerably. For example, we could take the frequency of the radiation emitted upon annihilation with antimatter as the “color” of the elementary particle, and that would be far in the gamma ray range. So it’s not visible to our eyes, but we can detect it with instruments. We cannot assign it a red, green, blue value corresponding to the narrow spectral range of what we perceive as visible light, but we can assign it some sort of abstract color value, or right away use wavelengths or the frequency of that radiation as the quantifier for “color.”
Cassius: Yeah, and we can’t even say really that it would be impossible for a creature with different eyes — you know, some other kind of capability. There are animals that can see colors that we can’t see, and we wouldn’t even know how to imagine them because they’re just not in our sensory experience.
Elaine: For humans who are — I guess what’s called color blind — people don’t see colors the same way.
Cassius: Right, right. That’s true too. Have you ever done one of those color tests where it tells you about the cone density in your eyes, whether you can distinguish fine differences in shades?
Martin: I have not. I think the only thing I’ve heard growing up was there’s something about you can’t be a pilot or an astronaut if you’re color blind.
Elaine: I mean, there are different types of color vision — different colors which certain people can’t distinguish. And by the way, there are certain jobs in my laboratory which I cannot assign to someone who is color blind, so every time we interview a person we run a color blindness test. It’s not a reason to not hire the person, but there are certain jobs we just can’t assign, because you need good color vision to do the analysis. And it’s not strictly binary color blindness — the discrimination between shades of the same color varies, and your sensitivity to very subtle shades can vary. I’ve read somewhere that women are more sensitive to yellow — more likely to be able to see it — and so babies in the newborn nursery who have jaundice: it may be that women can see that a little bit better. Though if it’s that subtle, clinically it’s probably not going to matter much. I’ve taken this test before to see whether I can distinguish between finer shades of color, and I have what they tested as the maximum number of cone density in my retina. I can tell super-fine shades. I might tell you your shirt and your pants don’t match, but you might not be able to see that they’re not the same color. Then there are animals that can see colors that we don’t even have words for because our retinas simply don’t do that.
Martin: That’s probably an argument that could have easily been incorporated within this section.
Cassius: Yeah, I would think so. Well, let’s look at the second paragraph, because I’m thinking that this whole section today has some deeper philosophical aspects that we need to address beyond the physics side. And the second paragraph has the section that says: “now every color may be changed one into another, but the principles of things will by no means admit of change; there necessarily must be something that remains immutable, lest all things should utterly be reduced to nothing; for whatsoever is changed and breaks the bounds of its first nature instantly dies and is no more what first it was.” He is linking the issue of color to the most fundamental question of existence, and I suspect Elaine in particular — but Martin as well — may have thoughts about that type of reasoning, because it’s not really physics-oriented as much as it is a much higher-level logical argument being employed against people who are fans of infinite divisibility. I want to hear what Martin says first.
Martin: Yeah, again, this is so weird from the viewpoint of what we now know about color. I mean, where we see color from is typically from what we call atoms or molecules, and these are composed bodies. So we see a transition between excitation levels in these composed bodies. And that one — except for this weird type of definition I gave before — there is no real meaningful color to be assigned to a fundamental particle in the normal sense. In a particular environment we can create complexes which are formally written as a bunch of compounds forming a complex around an electron, and then this complex appears blue. So we can tentatively assign blue as a “color” to the electron in this context — but if we change that setup, we may see an entirely different color, because what you see is the transition the electron makes between two excitation states. If we look at a dye, there will be specific transitions which the electrons make, and the color appears — but that electron is not different from any other electron. The color appears different because the complex is different. So this is not the color of the elementary particle, but rather of the composed body.
Cassius: Martin, before we shift back over to Elaine — let me ask you to focus particularly on this part of the passage. I think you can take this out of the color context and he holds to this principle regardless: “the principles of things will by no means admit of change; there necessarily must be something that remains immutable, lest all things should be utterly reduced to nothing.” What do you think of that?
Martin: Yeah, I mean, again, this is strange. We can conceive of a set of elementary particles which would have color, and that would not produce a problem. So I don’t really follow Lucretius here on the necessity of those elementary particles not having a color — and especially not in the dramatic sense he puts it here, that whatever has changed instantly dies.
Cassius: Martin, I think he’s going much further than referring just to color. He’s erecting the atomism system on the viewpoint that there is an ultimate particle of some kind that has unchanging characteristics — that is not created, does not die or disassemble itself, but is an ultimate, eternal particle with never-changing properties.
Elaine: Now, there’s no such thing as that. This is an example of where going beyond the evidence that you can observe can lead you to conclusions that don’t add up.
Cassius: Are you certain in saying that, though? And why?
Elaine: We don’t have any evidence of anything like that. I mean, we have matter and energy — it’s not like you get down to something that never changes. That’s what Alan pointed out.
Martin: Yeah, yeah, so there are no such permanently unchanging elementary particles. And again — I hope it won’t get boring to keep pointing this out — it is important to really stick to being cautious when you go beyond what you can actually make observations on. When you make extrapolations, some of them might be correct, but there’s a good chance that reasoning like that will lead you into the weeds.
Cassius: But it doesn’t matter in the big scheme of things, because it’s not necessary to have some kind of unchanging permanent particle to say that there’s no supernatural. You don’t need it. Before we go further on that: what is the basis on which you are making the statement that you’re certain no such particle exists?
Elaine: Okay — no, I’m going to be real cautious when I say this, to avoid sounding like a skeptic. Just so listeners understand: one of the central things for the skeptic is unknowability — they get really hung up on the fact that we can never know anything with 100% certainty, and that’s the most fascinating thing to them. I’m more into pragmatism — pragmatism wasn’t formally proposed during Epicurus’s time, but my personal philosophy incorporates it. And pragmatically: I can never tell you that there’s not such a particle. But nobody’s ever found one, and there doesn’t seem to be any necessity for one. So there’s no reason I have to believe in one. Somebody may come up with one someday — maybe. But we don’t know of one at this point.
Cassius: Okay. Those are two separate pieces: nobody’s ever found one — I don’t think anybody would argue with that; we’re all clear on that. What about the second piece, though? Because clearly that is what Lucretius is saying here: “there necessarily must be something that remains immutable, lest all things should utterly be reduced to nothing.” Is he not making a logical argument — and Martin, you’ve said this in the past about the difference between points and lines in geometry — is he not talking about an idealization? Lines that have no physical extension? Relate that back for me, Martin, because you know what I’m thinking.
Martin: It means there’s an idealization which we use in geometry, but we don’t claim that it actually exists in the real world.
Cassius: Well, we don’t — but there were these philosophers saying that infinite divisibility is the situation, and they were making that contention on purely logical grounds. They had never seen an atom, but they were asserting as a matter of philosophical principle that matter can be infinitely divided.
Martin: I think you’re confusing infinite divisibility with changeability. Those are two different things.
Cassius: Okay, but “lest all things should utterly be reduced to nothing” is related to infinite divisibility — I’ll agree they’re different, but they’re related. In this context, he’s talking about “be cautious how you stain the seeds of things with color, lest all things should recur to nothing” — there’s probably a distinction, but it’s also probably related. When these philosophers are saying there is infinite divisibility, Epicurus is rejecting that — but neither side has ever seen an atom, neither had an electron microscope or any of the technology we have today. They were approaching this from a theoretical, logical point of view. And so the issue of not having seen it does not get to addressing it on a logical level.
Martin: I mean, what we actually have is: particles which can be produced from something and which can be destroyed into something else. But what we see is: we observe only particles of defined types, and not something else. There are some particles which have, in some aspects, a continuous range of properties, but the nature of the particular particle always fits the classification we have based on defined physical properties. And that is the only thing we actually need to produce a world where we can see repetitive patterns. Something no more or no less than this may occur — not everything. So this one basically replaces the much simpler model from Epicurus, which said that elementary particles are eternal, indestructible, and cannot be created.
Elaine: Yeah, I mean, that’s good, because that’s what I was thinking. And Epicurus was right to reject making conclusions purely from reasoning and logic. You can make provisional ideas — theories, hypotheses — but you’ll be wrong a lot.
Cassius: Before we move on, I just want to be clear about what you’re both thinking about somebody who contends that matter is infinitely divisible. Obviously you’re saying Epicurus should apply the standard of “show me” — but you’d apply the same standard to the people asserting infinite divisibility?
Elaine: Obviously. All the time.
Cassius: So what is your position ultimately on whether things are infinitely divisible?
Martin: We see that things are orderly and reproducible. If things were always continuous without something elementary at the end, we would not see orderly phenomena as we see them now. We would not even have a word for “species” — one species typically has offspring of the same species. So not something that can be produced indefinitely by continuous division.
Cassius: Martin, in what you just said you’ve stated exactly the position that Lucretius is taking here, haven’t you?
Martin: Yes — but I’m talking about things that we observe. So it would be not just logically inconsistent with what we would observe, it would make what we observe impossible. This is a different kind of thing than going into proposing specific properties of the fundamental particles that we haven’t observed, and for which there could be more than one way things could work.
Cassius: The important point I’m hearing you make, though, is that you’re rejecting the contention that matter is infinitely divisible. But Elaine — are you also rejecting the contention that matter is not infinitely divisible? That Lucretius’s claim about immutability is also wrong?
Elaine: No, no, no, no. I’m rejecting that there are fundamental particles that are permanent and unchanging. The reason Lucretius got to that was he made too much of a leap — he went beyond what his observations told him. But I think matter not being infinitely divisible is something we have observed and concluded, versus the claim about the particles being permanently unchangeable. Those are different enough ideas. One is where he went too far beyond what he could observe, and one is where the observations actually support the conclusion.
Cassius: Okay, so you are very firmly and clearly separating the issue of immutability versus indivisibility.
Elaine: Yes.
Cassius: Martin, do you agree with that?
Martin: When I see this — to give an example of how his concept feasibly works out — he gives feasible models which in the end we now know are mostly wrong. But still, for that time, it was demonstrating how his system works and accounts completely for all natural phenomena without resorting to anything supernatural. That’s the benefit of these models, which have no real empirical backing at the level he’s proposing: they make it conceivable how you can explain the phenomena.
Cassius: Yeah, and so Martin — to wrap up on the distinction between immutable versus indivisible — your viewpoint on that is what?
Martin: The individual particle is not immutable, but the class of particles it belongs to — that is stable. We will always produce, under similar conditions, that same type of particle again, and it will again disappear into something else under comparable conditions.
Cassius: Okay. And with regard to indivisibility — you do not see science disputing that there is an ultimate particle that is ultimately indivisible?
Martin: Yeah, from the data, our models pretty much indicate this. We consider an electron as indivisible. For protons and neutrons, it’s a bit of a debate — these quarks do not really feel to me like particles in the way I would consider a particle. So we may consider protons and neutrons as elementary particles even though in the modeling we set them up as being composed of quarks. But again, the quarks do not really have the feel of particles to me. For photons, I would certainly classify them as elementary particles — and these can be, yes, for photons… they are easily annihilated and produced again.
Elaine: You see, Cassius, what Martin is talking about is observed behaviors — not extrapolating too far. He’s saying those things based on how they behave, based on technology far in advance of anything the Epicureans had two thousand years ago.
Cassius: Right, right, right. But still, the process of making observations — that’s not any different. I’m not letting them off the hook for going too far and making conclusions from observations, because I don’t want people today to think they’re doing something different. And that is one of the things I really liked when I read Epicurus — I don’t think he would have liked the concept of a “Day of Reason.” He would have wanted a “Day of Evidence.” But even someone like Epicurus — or Lucretius — can accidentally go too far. Well, any one of us probably could, too.
Okay, a lot of the rest of this passage today is probably right on point with what we discussed already. I would like to take a few minutes before we close today, though, to point out — and I’ll put this link in the notes for today’s show — that in Chapter 15 of A Few Days in Athens, Frances Wright comes back to this issue of color. I want to read a paragraph from Wright that is in a discussion about qualities of matter — about whether matter is inert or not, and what “inert” means. In the middle of that discussion, Frances Wright puts these words in the mouth of one of the characters, as if she thought this would probably be the Epicurean position: “What is in a substance cannot be separate from it, and is not all matter a compound of qualities? Hardness, extension, form, color, motion, rest — take away all these and where is matter? To conceive of mind independent of matter is as if we should conceive of color independent of a substance colored. What is form, if not a body of a particular shape? What is thought, if not something which thinks? Destroy the substance and you destroy its properties — and so equally destroy the properties and you destroy the substance. To suppose the possibility of retaining the one without the other is evident absurdity.” And I think the important part of this that relates to our discussion today is where she says “to conceive of mind independent of matter is as if we should conceive of color independent of a substance colored.” Apparently Aristotle, Theophrastus, and others asserted that color exists in the abstract. Now I think that relates to our discussion today — what do you guys think, does it relate at all? And if so, how? Martin, I’ll ask you first, because he won’t say anything unless I call on him directly.
Martin: Does color exist independent of an object which is colored? No — color comes from… it’s almost related to something. I mean, we can take just incoming color: then it’s transported by that photon. But once the photon is gone, that color impression doesn’t come back. And also, the origin of this is the matter which emitted it. The color we perceive comes from that matter, or that arrangement of matter in the case of interference colors. So that still fits.
Cassius: Elaine, what do you think? Does color exist independent of a substance which is colored?
Elaine: Oh, no. But — let me just throw in here that we have the ability to recall colors after having seen them. And I don’t know if that is what threw the idealists off — that because you could imagine it, it had to exist apart from what was colored. But your brain, when you’re doing that, is reproducing the processing that leads you to experience the color. And to me this also brings up the difference between something quantifiable — like the wavelength of light for a color — and qualia: what it feels like to see red versus the physics description of the color red. Obviously that’s happening in the brain and we know that, but it’s an experience. I think that’s probably relevant to what Frances Wright said.
Cassius: I think you’re right. I think where she’s going is that certain philosophers allege that there are reference ideals somewhere in the universe — that there is a perfect yellow, that all the yellow we see here is a reflection of yellow either in Plato’s world of ideal forms, or — and this second one is more related to what we’re discussing — apparently Aristotle decided that yellow does not exist in Plato’s world of ideal forms, but that there is an essence of yellow within an object.
Elaine: Yeah, that seems to be what Epicurus is objecting to. I think they’re mixing up qualia — they’re somehow getting confused about qualia. But I don’t know; it’s kind of hard to say why they went there. It doesn’t make any sense to me.
Cassius: I’m reminded that I’m dealing with a doctor and a physicist today, as opposed to somebody who gets really wrapped up in the logic of words and logical arguments. You’re right to take the attitude you do. It’s just frustrating that there are people who want to use words and concepts of ideas to come up with things that are so totally counterintuitive of what you would sense, what you would conclude from your experience. But I think that’s one of the reasons this section was important — as much as it may seem mundane or not necessary to some of us as we read through it. Do you see anything else in the rest of the text for today that we ought to comment on?
Elaine: No, and it’s not a particularly poetic passage. We’ve probably gotten everything out of it that we could get.
Cassius: Martin, any closing comments from you today?
Martin: Just to highlight a bit on the last paragraph: color is only visible with light, so if there’s no light, there is no color. And what we see in practice is that if we vary intensity, the color impression may change — the color saturation we perceive depends on the intensity with which we illuminate a colored object.
Cassius: Martin, that caused me to remember something I put in the notes for today. Do you see any analogy between the changing appearance of color — given the way the light strikes — and something we discussed back in Book One about the difference between events and properties? Back in Book One, he was talking about how the Trojan War was an event, an accident of a particular place and time. Is it pretty obvious — or not — that the discussion of color is analogous to that?
Martin: No — color has properties of both. Color is in some way a fundamental property of particular assemblies of matter. But on the other hand it changes under circumstances, and if it’s an interference color, it may change even radically — not only gradually. So color does not really fall into an either-or category like that.
Cassius: Okay — let me be even more specific by looking back at the passage. In Book One, there’s a list of qualities he referenced: “on the contrary, bondage, liberty, riches, poverty, war, peace, and the like — those are events.” Is color analogous to liberty, riches, poverty, war, and peace?
Martin: No, no — color is different. Like I said, it has elements of both these accidents and actual properties. For example: if you take a yellow object, and the yellow is just due to yellow paint, then under illumination it will always appear yellow — only the hue varies slightly with intensity and angle. So for this paint, color is really a characteristic property and not just an accident. But if we take a structured surface which produces interference color, then the color appearance depends heavily on the angle of incidence, and then the color appearance is more accidental.
Elaine: In both cases, though, it seems to me that it depends on both the material arrangement — the material properties of the surface. I don’t understand how those are necessarily totally different types of events. The surface itself is what it is, and when the light strikes it you’re going to see what you see.
Cassius: What if we ask the question not in terms of war and peace or liberty and bondage, but hot or cold — is the issue of hot or cold analogous to color?
Elaine: Well, you know, yes — what we’re going to perceive as hot or cold depends on what’s going on in the thing that we’re touching, but it also is relative to our own body temperature and our sensory nerves and what’s going to produce the sensation of hot, warm, or cold. All of our perceptions are subjective — they’re through our own organism. But that doesn’t mean that whatever we’re touching doesn’t have properties. A painted surface with what we see as yellow paint: in the dark, it still has the paint on it; the paint hasn’t changed. But we’re not going to see a color without the light.
Martin: For temperature, we can define an absolute scale and use a definition from there. So temperature is not just accidental — it’s not a fundamental property, but it’s not merely relative either.
Cassius: Well, it is certainly the case that by discussing this we are talking about an issue that needs to be thought about. And that’s the point I’m looking for. It is an interesting question whether — going back to the general point — so much of what we perceive is a matter not only of the thing we’re perceiving but also of our own organs of perception, our own ability to perceive, and the conditions under which we perceive. Those are the general reasons why we talk about so many things being contextual. But we also conclude that there’s a limit to the contextual aspect of things — that certain things exist independent of our perception of them. There’s a difference in the way you analyze these things, and it’s important for us to realize when we can apply the type of standards we apply to scientific observation versus what we can do to analyze our choices in life — even that’s not perfectly well said, but Elaine, what do you make of it? What is he saying about our approach to analysis when we think about how color is changing and why he insists that we should not believe color is intrinsic to an atom?
Elaine: Unless he brought in the subjective here explicitly — that to me, remembering always that there are things that we’re seeing that have color and we see them subjectively, that’s what gives us the experience of seeing color — so the important parts to me, the parts that are not really in here… I think this passage is interesting but it doesn’t lead me to any profound thoughts about my life decisions.
Cassius: Okay, right. And I don’t want to make more out of it than it has in front of us. But for me, always bringing in the remembering that we’re perceiving these things with our bodies — that’s very important.
Okay, we can probably leave it there for today and wrap it up. It’s always fascinating to me to go through the details of what he’s talking about and decide whether it has application to us — and if so, how — whether it’s something we should discard as an obsolete way of looking at things, or whether we can find anything in it that tells us about the reasoning process in a way that’s useful. By going through it in detail, I think we do learn a lot.
Elaine: I think so too.
Cassius: Okay. Well, with that we’ll wait for next week and tackle another aspect — probably still the atoms, but we’ll see. Martin, thank you. And I hope everybody has a good one.
Martin: Yes, same thing.