Posts by Cassius

George Berkeley is relevant to this discussion, so here's a summary of the issue there:

Berkeley's Subjective Idealism ("esse est percipi")

Berkeley attacks the very foundation Epicurus stands on — the reliability of sensation as a guide to external reality. Berkeley argues that material substance is an incoherent concept: all we ever actually have is perception, and "matter existing independently of mind" is something no one has ever experienced or could experience. Therefore minds and ideas are all that exist.

Epicurus's response would be aggressive and direct. Berkeley's argument is self-refuting by the Canon's standards: it uses the evidence of perception to deny the external world that makes perception intelligible. For Epicurus, sensation is not a veil between us and reality — it is a contact with reality. The eidōla (films of atoms) that strike our sense organs are literally from the objects perceived, carrying structural information about them. The causal chain from object to perception is physical and real.

More pointedly, Epicurus would note that Berkeley's "ideas in the mind of God" sustaining reality is simply the Platonic move in different dress — replacing the physical world with a mental/divine substrate that the Canon cannot reach. The argument is that Berkeley has traded one metaphysical claim (matter) for another far more extravagant one (universal divine mind).

We don't crawl in a hold and die and give way to AI because AI isn't alive, doesn't care, and will never fight for what it values as a human being. But if AI can help provide weapons of immediate value faster than we could find answers ourselves, I'm ready to pick up that weapon.

This answer is based on what living people have produced, but do I know any living person who can answer Aristotle better than this? If I do know such a person, please point out where the following might be wrong! Because it sure sounds consistent with all my past reading on Epicurus.

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The case of Aristotelian case is actually a harder problem for Epicurus than Plato's Ideal Forms, because Aristotle had already made the key concession Epicurus would demand of Plato.

Why It's a Different Problem

Against Plato, Epicurus's objection is relatively straightforward: Forms existing in a separate realm are simply unreachable by the Canon and do violence to the evident facts of reality consisting of bodies and void. Plato puts ideal forms or "essences" above the physical world.

Aristotle pre-empts that objection. He agrees there is no separate realm of Forms. Essences are immanent — they exist in particular things, not above them. The essence of color is not floating in a Platonic heaven; it is in colored things, and the intellect abstracts it from sensory experience. This is much closer to Epicurean territory, and Epicurus cannot simply dismiss it as empty transcendentalism.

The Epicurean Counter: Prolēpsis vs. Essence

The key Epicurean move is to deploy the doctrine of prolēpsis (preconception) as an alternative account of exactly what Aristotle thinks essences explain.

When we encounter red things repeatedly, we form a general mental concept — a prolēpsis — of color. This concept is real, it is useful, and it is derived from sensation. But for Epicurus it is a cognitive construction built from accumulated sensory encounters, not a perception of an immanent universal structure residing in things. The distinction matters enormously: Aristotle thinks the intellect is discovering something that is really there in the world; Epicurus thinks the intellect is constructing a useful generalization from what sensation provides.

So the Canon gives us particular colored things. Full stop. Aristotle's "essence of color" is what happens when a mind operates on that sensory data and mistakes its own generalization for a feature of external reality.

The Atomic Account Does Additional Work

On something like color specifically, Epicurus has a second line of attack: color is not a primary property of atoms at all. Atoms have shape, size, and weight — that is all. Color (and taste, sound, smell) are emergent properties arising from atomic arrangements in relation to a perceiver. They are real as experienced — Epicurus is not a skeptic about color experience — but they have no essence to be abstracted because they are relational and contextual, not intrinsic structural features of things.

This directly undercuts Aristotle's example. You cannot abstract the essence of color because color doesn't inhere in things as a stable immanent form waiting to be intellectually grasped. It is produced at the intersection of atomic structure and percipient organism.

The Teleology Connection

There is a deeper reason Epicurus must reject Aristotelian essence, and it goes beyond epistemology. Aristotle's essences are not merely descriptive — they are bound up with his teleology. The essence of a thing includes its telos, what it is for, what counts as its flourishing or completion. To ti ēn einai — "the what it was to be" for a thing — carries this purposive dimension throughout Aristotle's natural philosophy.

Epicurus rejects natural teleology root and branch. There is no "what things are for" in a world of atoms and void moving by weight, impact, and swerve. If there is no telos in nature, then Aristotelian essence — which is form-as-telos immanent in matter — simply has nothing to latch onto. The entire framework requires a purposive nature Epicurus denies.

Here's another logical conundrum: Why don't we just all crawl in a hole and die when AI can provide excellent answers that we might never be able to construct ourselves?

In the meantime while we ponder that, here's an articulate Epicurean response to Avicenna:

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Avicenna's argument is one of the most sophisticated theistic proofs ever constructed, and engaging it forces Epicurus to work at his deepest levels.

Avicenna's Argument in Brief

The Burhan al-Siddiqin runs roughly:

1. Something exists (self-evident)
2. Everything that exists is either contingent (possible — it could have not existed, its essence does not entail its existence) or necessary (it cannot not-exist; its essence simply IS its existence)
3. Contingent beings cannot account for their own existence — they require an external cause
4. An infinite regress of mutually contingent beings explains nothing — the whole chain remains ungrounded
5. Therefore there must be a Necessary Existent (Wajib al-Wujud) — a being that grounds all contingent existence
6. This is God

Its elegance is that it doesn't start with motion or causation in the ordinary sense — it starts with existence itself and the essence/existence distinction.

Epicurus's Responses

1. Reject the essence/existence distinction at its root

Avicenna's entire architecture depends on distinguishing, in contingent beings, what a thing is from that it is — essence from existence. The Necessary Existent is then defined as the one being where this gap collapses.

Epicurus would attack this as precisely the kind of empty abstraction the Canon cannot support. What sensation, prolepsis, or feeling gives you essence as a thing separable from an actually existing entity? These are scholastic constructions built in the mind, not features of the world the Canon attests to. The distinction is a linguistic and logical artifact, not a discovery about reality.

2. The matter and void are themselves the "Necessary Existent"

This is perhaps the sharpest Epicurean counter. Epicurus held that matter and void are eternal and uncreated — they have always existed and cannot not-exist. If Avicenna wants to say there must be something whose non-existence is impossible, Epicurus hands him atoms and void and says: here it is. You have simply re-described Epicurean first principles in theistic language and added nothing.

Avicenna would object that matter is still contingent in his sense — but Epicurus would reject the terms of that objection, since they depend on the essence/existence distinction already refused in point 1.

3. The infinite regress prohibition is simply asserted, not demonstrated

Avicenna claims a chain of mutually contingent beings cannot extend infinitely — that the whole chain would remain without a ground. But Epicurus explicitly and deliberately accepted an infinitely deep causal past. The universe has always existed; atomic interactions have no first moment. For Epicurus, demanding that a causal chain terminate is importing a logical intuition — that explanation must bottom out somewhere — and treating it as a metaphysical necessity. The Canon does not attest to this. It is an intellectual preference dressed as a proof.

4. The Canon directly blocks the conclusion

Following his standard methodology: the Necessary Existent is posited as something outside the natural world that grounds it. But Epicurus held that the gods, whatever they are, exist in the intermundia and are entirely uninvolved in the workings of the cosmos. More fundamentally, the concept of a being outside nature whose essence IS its existence is not derivable from sensation, prolepsis, or feeling. It is precisely the kind of concept generated by pure dialectical construction — the thing he was most suspicious of. No amount of formal validity in the argument licenses a conclusion that the Canon cannot reach.

5. The argument misuses "necessity"

Necessity for Epicurus is a property of arguments and propositions, not of beings as such. To say the atoms necessarily exist is a loose way of saying they have always existed and the evidence gives us no reason to think otherwise. It is not a deep metaphysical property inhering in them. Avicenna's move requires necessity to be an ontological feature that some beings have and others lack — a kind of modal metaphysics Epicurus would simply refuse to enter.

The Bottom Line

Epicurus would say Avicenna has constructed an impressive logical structure, but it is built entirely above the ground floor of what the Canon can support. The key moves — essence/existence distinction, the impossibility of infinite regress, the concept of necessary existence as an ontological category — are all products of pure dialectical reasoning untethered from sensation and experience. At each joint where the argument needs the world to cooperate with its logic, the world (as Epicurus understands it) simply doesn't.

And characteristically, Epicurus would not merely deflect: he would say the positive account — eternal matter, eternal void, infinite atomic motion with no first cause and no external ground — already explains everything Avicenna's argument was trying to explain, without requiring any entity the Canon cannot reach.

Also, in relation to how the atomism arguments fit in relation to the other logic-based issues:

Where the Common Thread Applies

The starting point is the same: Zeno's conclusion — that motion is impossible — is directly contradicted by sensation. We see things move. That is a Canon-level datum, and no formal argument can override it. So in that sense, Epicurus's first move is identical to his handling of the Liar or the Sorites: the argument reaches an absurd conclusion, therefore the argument is wrong.

But Here Epicurus Goes Further

With the Liar Paradox and the Sorites, Epicurus was largely content to dismiss the argument as a verbal or dialectical trap and move on. He didn't feel obligated to locate the precise flaw.

With Zeno's paradoxes he did something more demanding: he identified exactly where the argument goes wrong and replaced it with a positive physical theory. The false premise is infinite divisibility. Magnitude is not infinitely divisible — both atoms and the distances they traverse have genuine minima, smallest parts that cannot be further subdivided even conceptually. This doesn't just block Zeno's conclusion; it gives you a coherent account of how finite traversal of finite distances is physically possible.

The Deeper Point

So the minimal parts doctrine represents the Canon working at its most constructive. The Canon tells you the conclusion is false; reason then has the obligation to find the defective premise and build a correct account in its place. This is Epicurus at his most systematic — not just deflecting bad logic, but doing genuine physics in response to it.

It also shows that his anti-dialectical stance was not laziness or ignorance. When the stakes were high enough — when a logical argument threatened to undermine the entire intelligibility of the physical world — he would engage it fully on its own terrain and win on those terms.

I searched and added a series of other logic-based arguments, and this was suggested as the general common thread uniting the responses:

The Common Thread

What unites Epicurus's responses is a consistent methodological stance: formal logical arguments, no matter how clever, never override the Canon. If an argument leads to a conclusion that contradicts sensation, prolēpsis (common preconceptions), or the evidence of feelings, then the argument is wrong — even if you cannot immediately identify the flaw in its premises. This made Epicurus unusual in antiquity: he was not anti-rational, but he was firmly anti-dialectical in the sense that he refused to grant pure logic jurisdiction over empirical reality.

Infinite Regress Arguments for God as First Cause

While not exclusively Zeno-derived, various thinkers used infinite regress arguments to argue for a divine unmoved mover. Epicurus rejected the premise structure: he held that matter and motion are eternal and self-sufficient, requiring no external initiator. The infinite past of atomic motion is simply given — there is no logical compulsion to terminate a causal chain at a god.

(Need to expand)

Logical Fatalism / the Idle Argument (Argos Logos)

Related to the above, the Idle Argument ran: "If it is fated that you recover from this illness, you will recover whether you call a doctor or not; if it is fated that you do not recover, you will not recover whether you call a doctor or not; therefore calling a doctor is pointless." Epicurus attacked this as a practical reductio — the argument destroys the meaningfulness of deliberation and action, which are attested facts of experience. The atomic swerve was in part a physical mechanism designed to block precisely this kind of fatalistic conclusion.

Need references for this!

The Master Argument (Kyrieuon Logos) of Diodorus Cronus

This is perhaps the most philosophically important case. Diodorus constructed an argument that only the actual is possible — i.e., if something did not happen, it was never truly possible. This had direct bearing on Epicurean physics because it threatened atomic swerve (the parenklisis/clinamen): if determinism rules and only what occurs is possible, the swerve has no logical space to exist. Epicurus needed possibility to be real and open to preserve both the swerve and human free will. His counter was not to refute Diodorus's formal logic term by term, but to insist that the Canon and the evidence of human deliberative experience directly attest to real open possibility — and that no formal argument can override what is self-evident to experience.

(Need references for this)

The Liar Paradox ("This statement is false")

The Liar Paradox was a favorite of the Megarians (attributed to Eubulides). Epicurus famously dismissed it as not worth serious engagement — essentially calling it a verbal trick rather than a genuine logical problem. Cicero reports that he was criticized for this dismissiveness, but Epicurus held that the Canon grounds truth in relation to real objects of cognition, and a self-referential sentence with no object in the world simply falls outside the scope of genuine inquiry. His critics (especially the Stoics) thought this showed ignorance of logic; Epicurus would have said it showed wisdom about what logic is actually for.

(Need references for this)

Quote from Don

That said, I'm happy to leave the refutations to those inclined that direction.

RIght - those who are interested, please contribute; those who are not - no worries.

Yes done in general I agree - waste of time, at least for those of us who are familiar with the whole category of logical wordplay without reference back to physical / sense-based evidence.

However, we have a lot of people who come through the forum who aren't familiar with the overall issue, and how it relates not only to the "gods" question but also to the whole Epicurean sense-based canonics. The different forms of "Zeno's Paradoxes" are pretty much in the same category.

I think for that reason alone it would be good to develop a general framework of how all of these are defective in general, and how each one specifically fails to get around the fundamental flaw in the approach.

Just like on Youtube where people search for specific topics, if we set up a thread for each significant argument then the search engines will eventually pick up the threads and reach people with Epicurean arguments who otherwise would never find it.

So in this thread I'll focus the title on "General Responses To Logic-Based Arguments..." and those who are so inclined to address separate ones, please feel free to suggest separate threads. I'll moderate the forum structure to be sure this doesn't get out of hand, but if anyone who is a level 3 or above wants to set up specific threads please go ahead. Anyone else who is newer might want to add their suggestion to this list first.

This was brought up in a recent zoom meeting and I am posting it here for analysis of proper responses. We probably need a section for responses to these "Logical Proofs" arguments if we don't already have one.

Proof of the Truthful - Wikipedia

en.wikipedia.org

Glad to have you !

ReiWolfWoman tells us:

My background in Epicurus is that I was first exposed to him in an undergrad philosophy class, where we read some of his remaining work and that of Lucretius. Then in an online community where we discuss philosophy and improving quality of life, (as I have some previous exploration in stoicism as well as modern philosophy from childhood onwards). Then I read more of the book attributed to Epicurus and now I'm in the middle of Catherine Wilson’s How to Be an Epicurean.....

Welcome ReiWolfWoman

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This forum is the place for students of Epicurus to coordinate their studies and work together to promote the philosophy of Epicurus. Please remember that all posting here is subject to our Community Standards and associated Terms of Use. Please be sure to read that document to understand our ground rules.

Please understand that the leaders of this forum are well aware that many fans of Epicurus may have sincerely-held views of what Epicurus taught that are incompatible with the purposes and standards of this forum. This forum is dedicated exclusively to the study and support of people who are committed to classical Epicurean views. As a result, this forum is not for people who seek to mix and match Epicurean views with positions that are inherently inconsistent with the core teachings of Epicurus.

All of us who are here have arrived at our respect for Epicurus after long journeys through other philosophies, and we do not demand of others what we were not able to do ourselves. Epicurean philosophy is very different from most other philosophies, and it takes time to understand how deep those differences really are. That's why we have membership levels here at the forum which allow for new participants to discuss and develop their own learning, but it's also why we have standards that will lead in some cases to arguments being limited, and even participants being removed, when the purposes of the community require it. Epicurean philosophy is not inherently democratic, or committed to unlimited free speech, or devoted to any other form of organization other than the pursuit of truth and happy living through pleasure as explained in the principles of Epicurean philosophy.

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We have found over the years that there are a number of key texts and references which most all serious students of Epicurus will want to read and evaluate for themselves. Those include the following.

"Epicurus and His Philosophy" by Norman DeWitt

The Biography of Epicurus by Diogenes Laertius. This includes the surviving letters of Epicurus, including those to Herodotus, Pythocles, and Menoeceus.

"On The Nature of Things" - by Lucretius (a poetic abridgement of Epicurus' "On Nature"

"Epicurus on Pleasure" - By Boris Nikolsky

The chapters on Epicurus in Gosling and Taylor's "The Greeks On Pleasure."

Cicero's "On Ends" - Torquatus Section

Cicero's "On The Nature of the Gods" - Velleius Section

The Inscription of Diogenes of Oinoanda - Martin Ferguson Smith translation

A Few Days In Athens" - Frances Wright

Lucian Core Texts on Epicurus: (1) Alexander the Oracle-Monger, (2) Hermotimus

Philodemus "On Methods of Inference" (De Lacy version, including his appendix on relationship of Epicurean canon to Aristotle and other Greeks)

"The Greeks on Pleasure" -Gosling & Taylor Sections on Epicurus, especially the section on katastematic and kinetic pleasure which explains why ultimately this distinction was not of great significance to Epicurus.

It is by no means essential or required that you have read these texts before participating in the forum, but your understanding of Epicurus will be much enhanced the more of these you have read. Feel free to join in on one or more of our conversation threads under various topics found throughout the forum, where you can to ask questions or to add in any of your insights as you study the Epicurean philosophy.

And time has also indicated to us that if you can find the time to read one book which will best explain classical Epicurean philosophy, as opposed to most modern "eclectic" interpretations of Epicurus, that book is Norman DeWitt's Epicurus And His Philosophy.

(If you have any questions regarding the usage of the forum or finding info, please post any questions in this thread).

Welcome to the forum!

As to the work of Steve Patterson outside the video, I can save people some time about where he stands:

Coming Around to Platonism – Steve Patterson

OK i have watched the video and now I have another way of asking my last question:

1. Lamar_44 thinks the Patterson video is "good" and useful.
2. Martin thinks the Patterson video is a "bad" and a waste of time.

What explains the very different reactions to the video between two people who (by virtue of being here at EpicureaFriends) presumably look at basic issues of reality from a somewhat similar perspective?

Maybe that's just another way of asking the same question, or maybe that's more interesting and more useful for forum purposes than the question presented in the video itself.

@Lamar_44 I note Martin's comment and as soon as I have time will watch that myself.

What conclusion do you reach based on that video?

The entire question of imagination and thought experiments definitely has interest for some people. If Zeno wants to imagine infinite divisibility and construct hypotheticals based on it, then in a free world he has a right to do that, and if it gives him pleasure then more power to him.

I see that the video starts out asking whether a series of math statements getting increasingly smaller really "equals" zero, and the obvious answer is that of course it doesn't because you're defining the question in a way that doesn't mean exactly the same thing as zero.

Do such experiments have practical uses? Probably so - math has lots of practical uses.

But if the purpose of thought experiments is to confuse other people and make them doubt practical reality, then that is not just innocent fun and games, but harmful to real people.

Where do you see all this going and what benefits derive from exploring the things that people can imagine without first establishing that what they imagine is real?

LAMAR__44 thank you for your posts in the forum so far. You have asked some good questions that are asked regularly, so I am glad we've had the opportunity to discuss them.

However I note that you have not said much about your own positions or offered much in the way of your own personal agreement or disagreement with Epicurean philosophy.

Can you please elaborate on that?

While asking good questions is helpful, we are not a general philosophy forum, and we do want to make sure our time is being used most productively toward the goals of the site.

Thanks

Presuming first that we are communicating as to "universe" meaning "the all" and not just "our universe" then I'd go back to the very first part of your first post.

Quote from LAMAR__44

Essentially, it argues that the universe could not be eternal, since this would require an infinite past.

I doubt Epicurus would go much past that without stating that "the universe / the all" must be eternal, because it is inconceivable that there was ever a time in which "the all" did not exist. It certainly appear to us that the we exist, and that it makes no sense to consider that there was ever a time that the all did not exist, so I would rule out of hand any supposition (it would require an infinite number of steps to get here and that's not possible) that conflicts with what all appearances tells us does exist.

I'm sure someone here can probably do better than that for an answer but any fundamental logical paradox like that has to be resolved in the end by relying on the apparences (sensations) which in the end are all we have as contact with reality. The mind can image all sorts of constructions that defy reality, but devotion to what nature has given us is why in the end we go with sensations and not with pure logic that ultimately cannot be reconciled with the senses.