Posts by Cassius

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Essentially, it argues that the universe could not be eternal

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This point is consistent with Epicurean physics, which teaches that each kósmos is temporary.

And I agree with Eikadistes there Lamar_44. Eikadistes is using what is apparently the current terminology. I use the terminology I grew up with - "universe means everything - the all." As I read it we end up in the same place.

Quote from Eikadistes

I'm speaking personally here, but I disagree with this on the premise of Karl Popper's delineation between verification versus falsifiability. Verification says that we have to experimentally verify things for statements to be true.

This is a recurring theme of some recent discussions here. Call it a matter of terminology or whatever, but I (and I think Epicurus and those who followed him on canonics did so) maintain that it is ridiculous to assert that before you can "know" something you must have "been there done that yourself."

Quote from Eikadistes

But, here again, it might be better not to use ancient categories to organize the concepts we derive from modern observations.

And I would say that it also would be better not to let modern observations cause us to lose sight of ancient categories when those categories still serve a useful purpose and those categories are not comprehensively contradicted by those modern observations.

For example I would say that just because the observable universe appears to be expanding, that does not compel us to conclude that the universe as a whole is not infinite in size or eternal in time. Some disagree, but I think those conclusions remain logically persuasive. And if you say "no the universe is neither eternal nor infinite" then the practical result is not "truth," (which the "no" chorus does not advocate for anyway) but the opening of the door to the presumption that 'god' is what existed before the universe (it if came into being at some point) or outside the universe (if the universe is not infinite in size).

Again, not everyone here agrees with my point of view on that, but (1) as far as I can tell that is what Epicurus held, and (2) the position that Epicurus held is of far greater understandability and practical benefit for non-specialists than the unending and unverifiable speculation that many want to substitute in its place.

If someone disagrees with my reading of Epicurus, please be sure to correct me.

Thanks to Eikadistes for an excellent post.

It appears for some reason that this thread was closed in error, as I don't see another one treating the same article by Sedley. It's directly relevant to issues of knowledge and probability so I am bumping it for reference in current discussions.

Sound to me like that's a variation of the Zeno argument that you cannot move or walk across the room because there are infinite steps in between.

Someone else ( Joshua ) probably can state the response better than me, but Epicurus rejects the argument that matter is infinitely divisible so as to make motion impossible, and that presumably would apply to this question as well.

As to conceptualizing infinity that's an excellent question too. I presume part of the answer there is that it would be more difficult to conceptualize an END to space or number of atoms than it would be to conceptualize unlimited amounts of both. That's the argument that is stated at length in Lucretius Book One at 968 in more detail (including the javvelin argument) than is included in the letter the Herodotus.

Again as with your other question I think you're touching on something where we have at least some relevant information in Philodemus' "On Signs," this time under the heading of "inconceivability."

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Quote from LAMAR__44

Perhaps it’s that we wouldn’t feel a continuation of existence like we do now,

Perhaps Tau Phi's post mentions this (haven't read it yet) but your specific question is addressed by Lucretius. His answer is as you indicate, that our exact atoms could reassemble in the future, but that we would have no memory of it so it would not be us in actuality.

I think your question of why the memory would not reassemble is also a good one, but as I understand Lucretius his answer is that we would not expect that because human experience is indeed that we now have no memory of past lives, so we would not expect that past experience to change. That's an issue that bleeds over into Epicurean canonics in general and Phildemus' On Signs in particular, as a question of when we have enough information to infer that we are confident of the answer. I would expect this to be one of those times.

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3-843

And even if the nature of mind and the power of soul has feeling, after it has been rent asunder from our body, yet it is naught to us, who are made one by the mating and marriage of body and soul. Nor, if time should gather together our substance after our decease and bring it back again as it is now placed, if once more the light of life should be vouchsafed to us, yet, even were that done, it would not concern us at all, when once the remembrance of our former selves were snapped in twain. And even now we care not at all for the selves that we once were, not at all are we touched by any torturing pain for them. For when you look back over all the lapse of immeasurable time that now is gone, and think how manifold are the motions of matter, you could easily believe this too, that these same seeds, whereof we now are made, have often been placed in the same order as they are now; and yet we cannot recall that in our mind’s memory; for in between lies a break in life, and all the motions have wandered everywhere far astray from sense.

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Given that many of our recent discussions have focused on identifying the Epicurean position as to knowledge, and whether "probability" is the best we can do on any topic, I've produced using Claude an initial outline of the analysis of Philodemus made by DeLacy and Sedley. The current result seems to me to accord with my prior reading from both sources, and this outline brings the sources and references together in a much tighter presentation that we've had available before.

Just to be clear, it is a primary goal of EpicureanFriends.com to produce accurate and understandable material to help new people develop a general level of understanding of Epicurus. Even after ten years of online activity, we've previously only scratched the surface of review of this work by Philodemus, despite the fact that it clearly and firmly addresses one of the most controversial aspects of Epicurean philosophy. These are issues we are grappling with now on the Lucretius Today Podcast, and we're going to turn even more directly to them when we finish Academic Questions and move directly to this book.

if you have an absolutist rejection of all use of AI in philosophical work, you certainly are under no obligation to read any of all of this document. If, on the other hand, you're in tune with the urgency and desirability of using any tool possible to better understand Epicurean philosophy and explain it to others, then I welcome your review of this summary and your suggestions for improving it. Please post those in the thread linked below.

The full version of the current analysis outline at EpicurusToday.com:

Philodemus - On Methods of Inference - Outline and Analysis

Forum thread for discussion, comments, suggestions:

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Analysis of Epicurean Canonics

I have asked ClaudaAI to take the DeLacy translation and commentary, as well as Sedley's essay On Signs, and produce a detailed outline and analysis of the work based on those two authorities. After reviewing the result it looks pretty good to me, and extremely useful.

Given it's length and easier presentation in markdown format than here, I'll link it first (where it is easier to read). The full text follows after the link. Given the duplicate effort in maintaining two copies I will probably…

Cassius

April 6, 2026 at 10:39 AM

Robert I have completed my first review of the full Claude summary, and it appears to me to be excellent. For ease of followup I would appreciate further comments on this topic being made over there so we can keep most of the discussion in the Philodemus subsection:

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Analysis of Epicurean Canonics

I have asked ClaudaAI to take the DeLacy translation and commentary, as well as Sedley's essay On Signs, and produce a detailed outline and analysis of the work based on those two authorities. After reviewing the result it looks pretty good to me, and extremely useful.

Given it's length and easier presentation in markdown format than here, I'll link it first (where it is easier to read). The full text follows after the link. Given the duplicate effort in maintaining two copies I will probably…

Cassius

April 6, 2026 at 10:39 AM

I have asked ClaudaAI to take the DeLacy translation and commentary, as well as Sedley's essay On Signs, and produce a detailed outline and analysis of the work based on those two authorities. After reviewing the result it looks pretty good to me, and extremely useful.

Given it's length and easier presentation in markdown format than here, I'll link it first (where it is easier to read). The full text follows after the link. Given the duplicate effort in maintaining two copies I will probably update the epicurustoday.com version more frequently, so I advise referring to that one. (especially since at the moment the forum version is irritatingly converting some punctuation to smiley faces!)

EDIT -- As of 4/7/26 I have already made significant revisions to the document, and I see that it's not going to be feasible to maintain two copies at least until the revisions begin to slow. Please refer to the version at EpicurusToday.com for the latest version.

What conclusion would you reach if there were such influence?

At this meeting Robertbravely attempted to summarize aspects of Philodemus' "On Methods of Inference / On Signs" as to where Philodemus comes down on whether positions can constitute"knowledge" or rise only to "probability."

If i recall correctly Robert thought that Philodemus came down on the side off "probabiiity." I was not able to confirm or deny that.

At this moment I still can't, and firm positions are going to have to wait until we can devote more time to review of that work.

However I don't want to leave the conversation as is without some degree of followup, so here is what Claude says when I asked it to compare the Delacy commentary and the Sedley commentary with the DeLacy translation. I'm going to pursue this much further but here is the summary. Take it for what it is worth, but I will say that the following makes sense to me given my current state of understanding Epicurus.

IX. SUMMARY OF PHILODEMUS' POSITION

Philodemus defends the following set of claims, which together constitute the Epicurean philosophy of knowledge:

1. All perceptions are true in the sense of faithfully presenting the appearance that occurs. Error arises only from additional opinion.
2. Inference from perception, properly conducted, is genuine knowledge — not merely probable. The properly-made analogical inference carries the same epistemic status as perception itself (Frag. 2).
3. The criterion of inconceivability converts inductive inference into claims of necessity. When it is genuinely inconceivable (on the basis of broad empirical observation) that the sign could exist without what it signifies, we have established a necessary connection.
4. Non-contestation (ouk antimarturēsis) is a sufficient condition for truth when combined with explanatory power. A theory that conflicts with no phenomenon and explains what needs explaining is genuinely true (for basic physics), not merely probably true.
5. The elimination method is not independently valid but derives whatever force it has from the prior work of the similarity method. Stoic deduction is epistemically downstream from Epicurean induction.
6. The Stoic pithanon classification is rejected for properly-conducted empirical inference. It may apply to careless or premature inferences; it does not apply to inference conducted with wide and varied observation, correct identification of relevant qualities, and confirmed by non-contestation.
7. Degrees of certainty exist within the class of warranted inferences: some inferences are more secure than others, depending on the uniformity and breadth of the evidence. But the existence of more and less secure inferences does not mean that the more secure ones are merely probable.
8. The limits of knowledge are real: some things (the parity of the stars) are genuinely unknowable; for celestial phenomena, multiple explanations may all be equally acceptable; for basic physics, uniquely determined truth is achievable.

In short, Philodemus' position is a robust empirical foundationalism: the senses give us infallible access to appearances; properly-made inferences from appearances give us genuine, necessary knowledge of the unperceived world. This is neither scepticism (knowledge is impossible) nor rationalism (knowledge requires a priori foundations). It is a demanding empiricism that claims genuine knowledge of atoms, void, and unperceived objects throughout the universe.

Quote from LAMAR__44

So friendship is defined as pleasure created when two or more beings cooperate, as it benefits all parties in fulfilling their own needs, but it emerges into something greater? Either weak emergence where we still map it onto satisfying personal pleasure, but we gain pleasure from viewing the other person’s needs as our own, or is it strong emergence where as the value of friendship now is above just the value of pleasure?

I don't think Epicurus would consider "the value of friendship above the value of pleasure"

His wider framework is clearly to divide all feelings into pleasure and pain with only pleasure desirable in and of itself. So I think that observation answers your specific question about ranking - friendship is among the pleasures, not "above" pleasure. (Remembering of course that for Epicurus "pleasure" is an extremely broad term that covers everything in life that is desirable.)

I am not familiar with Epicurus dividing emergence into weaker or stronger - only in the materials we have been qualties that are necessary to the identity of the things vs those that are "events" that can change without the thing itself being destroyed.

Certainly pleasures are not all identical, in that they effect different parts of the body, have different intensities, and different durations. And Epicurus refers to "greater pleasure" in the letter to Menoeceus so it would not be necessary to think of friendship as being more than one of the greater - or perhaps greatest - sources of pleasure.

Quote from LAMAR__44

something that can’t just be thought of as the sum of its parts but something greater? Like the mind being created by the brain but being above it in a way where you can’t reduce the mind to each neuron in the brain?

This is a subject that we have not explored deeply here at the forum, with Sedley's "Epicurean Anti-Reductionism" only recently being first discussed. References to "both levels (atomic and our world level) being real has been discussed as a result of Sedley's "Epicurus' Refutation of Determinism" article mentioned for several years, but even that has not really explored in depth.

I think the answer to your question is probably what your wrote that I have quoted above. For example water is something that most of us probably consider very much more than "the sum of its parts" (atoms of hydrogen and oxygen) . But it would be essential to keep in mind the emphatic limitation that consideration of the emergent quality never crosses over into a "supernatural" quality that implies the existence of an otherworldly intelligence.

This is a great question and no doubt discussion of it will be scattered throughout the forum in the future. Pleasure as discussed in this thread is absolutely one part of the question, as is determinism. For now the original and probably wider discussions are probably focused in these threads:

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Connecting Thought With Atoms - Emergence, Downward Causation (From The Macroscopic To The Atomic), and Epicurus

In today's Zoom and also podcast this issue was discussed as a result of David Sedley's article "Epicurean Anti-Reductionism." The basic concept as I understand it it likely this:

Epicurus would have understood just as we do today that it is not intuitive how atoms, which have no properties other than shape, size, and weight, can no matter how they combine have the ability to think and assume all the other complex phenomena that we see around us. In even simpler terms, how can atoms which do not…

Cassius

March 29, 2026 at 3:22 PM

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Article - David Sedley - 1988 - "Epicurean Anti-Reductionism"

We've referenced many times on the forum the comments about this topic made by David Sedley in his "Epicurus' Refutation of Determinism."

I don't think we previously cited - or that I knew of - an article Dr. Sedley had written directly on point:

Epicurean Anti-Reductionism - 1988 - J. Barnes, M. Mignucci (eds.), Matter and Metaphysics (Naples 1988), 295-327

Full article available here:

https://www.academia.edu/3051123/Epicurean_anti_reductionism

Summary of Main Arguments and Highlights

1. Core

…

Cassius

March 26, 2026 at 9:13 AM

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Sedley: "Epicurus' Refutation of Determinism"

This is the thread for discussion of the Sedley article on Epicurus' Refutation of Determinism. This is BY FAR the best treatment of this subject I have ever read, and I highly recommend it to everyone who participates in this forum.

David Sedley is an outstanding scholar who is generally very sympathetic to Epicurus, and this article brings together the familiar passages from Lucretius with Sedley's interpretations of Herculaneum fragments from Epicurus' "On Nature." The result is a persuasive…

Cassius

June 3, 2020 at 8:43 AM

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My first reaction would be 'both' - given that the context seems to be that he is considering things for which we are responsible , and everything that you're listing seems to be at least somewhat arising from our own choices.

I am likely to eventually break this out into a discussion of its own, but in this episode of the podcast Joshua brings up the question of "doxa" vs "episteme." From wikipedia:

Doxa (Ancient Greek: δόξα; from verb δοκεῖν, dokein, 'to appear, to seem, to think, to accept')^[1] is a common belief or popular opinion. In classical rhetoric, doxa is contrasted with episteme ('knowledge').

We're having many simultaneous discussions about these issues right now, and it seems to me to be a good idea to try to be as clear as possible on what Epicurus considered to be "knowledge" vs what he considered to be "opinion."

"Knowledge" is a term to me that seems pretty clear, but probably "opinion" needs clarification as to whether "opinion" (as a word standing alone) is always to be viewed with suspicion, (probably yes?) while "knowledge" (as a word standing alone) implies something much more firm.

So that's something that needs to be clarified, but after that, the big issue is deciding what Epicurus held to be "known" and therefore relied upon with confidence vs "opinion" in which probability might be the best that can be said for it.

Specifically, as examples, did Epicurus hold PD01 and PD02 as written to be "knowledge" or some lesser standard, better described as "opinion."

Clearly Epicurus held many things mentioned in the letter to Pythocles to be open to numbers of possibilities, so as to those mostly astronomical issues I'd say those are "opinion."

But what about the affirmative statements in PD01, PD02? We'll also want to consider the many affirmative statements made in the letter to Menoeceus, and the most general of statements in Herodotus, but we ought not bite off more than can be chewed too quickly.

Were the positions stated in PD01 and PD02 considered by Epicurus to be "known" (knowledge)? Would he have admitted any aspect of them to be only "probably" true?

EDIT: It will presumably be important to incorporate as primary sources:

1. What Lucretius says about this topic in Book 4 (a very long section but especially here
2. What Diogenes of Oinoanda has to say about this in Fragment 5.

   1. Fr. 5 [Others do not] explicitly [stigmatise] natural science as unnecessary, being ashamed to acknowledge [this], but use another means of discarding it. For, when they assert that things are inapprehensible, what else are they saying than that there is no need for us to pursue natural science? After all, who will choose to seek what he can never find? Now Aristotle and those who hold the same Peripatetic views as Aristotle say that nothing is scientifically knowable, because things are continually in flux and, on account of the rapidity of the flux, evade our apprehension. We on the other hand acknowledge their flux, but not its being so rapid that the nature of each thing [is] at no time apprehensible by sense-perception. And indeed [in no way would the upholders of] the view under discussion have been able to say (and this is just what they do [maintain] that [at one time] this is [white] and this black, while [at another time] neither this is [white nor] that black, [if] they had not had [previous] knowledge of the nature of both white and black.

So regardless of the rest of the implications, one of the basic questions is apparently: Did Epicurus number friendship as being among the virtues? (Or considered under the category name "virtue.")

I am inclined to agree with the excerpts Don posted to the effect that the answer is "Yes." ("Yes - friendship is a virtue.")

Does anyone (TauPhi perhaps?) disagree with that?

I am presuming Don that you do agree?

Welcome to Episode 328 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.
   
This week we start are continuing our series reviewing Cicero's "Academic Questions" from an Epicurean perspective. We are focusing first on what is referred to as Book One, which provides an overview of the issues that split Plato's Academy and gives us an overview of the philosophical issues being dealt with at the time of Epicurus. This week will focus on the ending of Section 8.

Our text will come from
Cicero - Academic Questions - Yonge We'll likely stick with Yonge primarily, but we'll also refer to the Rackam translation here:

• Cicero On Nature Of Gods Academica Loeb Rackham : Free Download, Borrow, and Streaming : Internet Archive

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VIII.

The third part of philosophy, which is next in order, being conversant about reason and discussion, was thus handled by both schools. They said that, although it originated in the senses, still the power of judging of the truth was not in the senses. They insisted upon it that intellect was the judge of things. They thought that the only thing deserving of belief, because it alone discerned that which was always simple and uniform, and which perceived its real character. This they call idea, having already received this name from Plato; and we properly entitle it species.

But they thought that all the senses were dull and slow, and that they did not by any means perceive those things which appeared subjected to the senses; which were either so small as to be unable to come under the notice of sense, or so moveable and rapid that none of them was ever one consistent thing, nor even the same thing, because everything was in a continual state of transition and disappearance. And therefore they called all this division of things one resting wholly on opinion. But they thought that science had no existence anywhere except in the notions and reasonings of the mind; on which account they approved of the definitions of things, and employed them on everything which was brought under discussion. The explanation of words also was approved of — that is to say, the explanation of the cause why everything was named as it was; and that they called etymology. Afterwards they used arguments, and, as it were, marks of things, for the proof and conclusion of what they wished to have explained; in which the whole system of dialectics — that is to say, of an oration brought to its conclusion by ratiocination, was handed down. And to this there was added, as a kind of second part, the oratorical power of speaking, which consists in developing a continued discourse, composed in a manner adapted to produce conviction.

It occurs to me to add here that in some of our physics discussions recently we have had reason to focus on the importance of "emergence" or "emergent qualities" to the nature of the way things are.

Probably friendship and love and the issues you are talking about have an analogy there.

At the beginning of any relationship there are simple and direct interactions, but over time those deepen and expand and something emerges that is far different from what was present at the beginning.

For example there's a world of difference between buying a hamburger at a counter and living together for decades, raising a family, etc. And yet the latter type of relationship can emerge from the former, and it is completely proper to consider both of relationships as true and real and proper, and in no way is one less real or conflicting with the other.

This entire issue of emergence is the path by which we escape the false idea of intelligent design, arbitrary gods, and eternal punishment after death. i don't know that we have record of it being applied in exactly that way but it would be surprising if this example of pleasure weren't related to the way Epicurus analyzed the universe as a whole -- as emerging from simpler starting points.

These week we will continue around section 1:305 of Lucretius and explore further the implications of the invisibility of atoms and how we can have confidence in something that is not visible. This week we go over Lucretius' specific examples of how we reach this conclusion by analogy.

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Just a little more on this (admittedly largely repeating what I already wrote, but for emphasis):

Quote from LAMAR__44

This isn’t me arguing against hedonism,

Consistent with what I wrote about above - there's no problem here in arguing against "hedonism." - I will help you in fact, given that I think it's a poor idea to talk about Epicurean philosophy as "hedonism" in any but very limited circumstances. Those who try to pursue or promote "hedonism" outside the framework of Epicurean philosophy -- especially the wider meaning of "pleasure" that Epicurus uses - do have the problems you are concerned about.

It would appear that somewhere you've picked up that there is in fact a "paradox of hedonism" and that's why I titled the new thread that way. No doubt you're right that a lot of people talk that way on Reddit and elsewhere, but there's no reason to accept the terminology of anti-Epicurean thought here at EpicureanFriends.com. It's no paradox - there's a straightforward way of addressing the question.