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:

Epicurean anti-reductionism

Epicurean anti-reductionism

www.academia.edu

Summary of Main Arguments and Highlights

1. Core Thesis: Epicureanism is Not Fully Reductionist

Sedley’s central claim is that Epicurean philosophy, although grounded in atomism, cannot be understood as a purely reductionist system.

• While everything is composed of atoms and void, Epicurus does not reduce all explanations to atomic properties alone.
• Instead, Epicureanism allows for higher-level explanations that are not eliminable into micro-level physics.

Key implication:
Epicurus is a qualified materialist, not a strict reductionist.

2. Distinction Between Atoms and Compounds

Sedley emphasizes a crucial distinction:

• Atoms: possess only a few immutable properties (shape, size, weight).
• Compound bodies: exhibit qualities that do not belong to atoms themselves.

This aligns with Lucretius’ distinction between:

• Coniuncta (necessary qualities)
• Eventa (accidental qualities)

These qualities:

• Depend on atomic arrangements
• But are not reducible to atomic descriptions

3. Emergent Qualities Are Real (Not Illusions)

A central anti-reductionist point:

• Qualities like color, heat, solidity, life, and agency are:
  • Not properties of individual atoms
  • Yet genuinely real features of compound bodies

Sedley stresses that Epicurus:

• Does not treat these as mere appearances or illusions
• Instead treats them as objective, though derivative, realities

Conclusion:
Epicureanism supports a form of emergence—higher-level properties arise from but are not identical to lower-level constituents.

4. Explanatory Pluralism

Sedley argues that Epicurus uses multiple levels of explanation simultaneously:

• Micro-level: atoms and their motions
• Macro-level: observable phenomena and qualities

These levels are:

• Compatible, but
• Not interchangeable

Thus:

• Some explanations are best given at the level of bodies, not atoms.

5. Rejection of Eliminative Reductionism

Epicurus rejects the idea that:

Quote

Only atomic-level facts are “really real”

Instead:

• Observable properties retain explanatory legitimacy
• Everyday descriptions (e.g., “fire is hot”) are philosophically valid

This is a direct rejection of:

• The view that higher-level properties must be eliminated in favor of physics

6. Stability and Identity of Objects

Sedley highlights that:

• Compound bodies have stable identities
• These identities depend on:
  • Structural organization
  • Functional roles

Not merely:

• A list of atomic constituents

Thus:

• A thing’s identity is tied to its emergent organization, not just its atoms

7. Ethical and Psychological Implications

This anti-reductionism is not merely physical—it extends into ethics:

• Human experiences (pleasure, pain, fear) are:
  • Grounded in atomic processes
  • But must be understood at the level of lived experience

Epicurus therefore:

• Treats psychological states as real and explanatorily significant
• Not reducible away into physics

8. Lucretius as Key Evidence

Sedley relies heavily on On the Nature of Things to support this interpretation:

• Lucretius explicitly distinguishes:
  • Atomic properties
  • Emergent qualities of bodies
• He shows that:
  • Qualities arise from arrangements and interactions, not intrinsic atomic features

Overall Interpretation

Sedley’s interpretation can be summarized as follows:

• Epicurus is a materialist → everything is made of atoms and void
• But also an anti-reductionist → not everything can be explained purely at the atomic level

This results in a philosophical position that combines:

• Ontological reduction (everything is atoms)
• With explanatory pluralism (not everything is explained in atomic terms)

Concise Takeaway

Quote

Epicurean philosophy holds that while atoms are the fundamental constituents of reality, the world we experience—including qualities, objects, and human life—must be understood at their own level and cannot be reduced away into atomic descriptions.

There's a LOT of interest in that article. Here's a section that both interesting and "funny" as to what should probably be our love-hate relationship with Cyril Bailey:

In this article Sedley refers several time to aetiology and ontology and discusses which aspect is primary to Epicurus on a particular point. It might help to have this explanation before reading the article (pasted from our good friends at ChatGPT):

The phrase “aetiologically rather than ontologically primary” distinguishes two different senses in which something can be considered “primary” or fundamental.

1. Aetiologically primary (causally primary)

• Aetiology means cause or explanation of origin.
• If something is aetiologically primary, it is:
  • The cause or source of something else
  • What explains how or why something comes to be

👉 In simple terms:
It comes first in the order of explanation or causation.

2. Ontologically primary (being primary)

• Ontology concerns what exists and what is fundamentally real.
• If something is ontologically primary, it is:
  • More fundamental in reality
  • What other things depend on for their existence

👉 In simple terms:
It comes first in the order of being or reality.

Thanks for your question, Dave. It comes up frequently so I have updated the FAQ. Here's the short version:

Epicurus would be the last person to insist we cling to 2,000-year-old technical details in physics just because he said them. He was emphatically committed to observation and experience over authority — including his own. So when you say modern physics has advanced what Epicurus encouraged, I agree completely. The question is really: what specifically did Epicurus encourage in the area of physics, and why does it still matter to how we live?

Here's the crux: Epicurean physics was never really about the technical details of atoms for their own sake. It was constructed to do a specific job — to address three towering sources of human misery:

1. The fear that supernatural gods are watching us, judging us, and will punish us after death.

2. The fear that the universe is governed by Fate or Necessity, that nothing we do matters, and that we have no real agency in our own lives.

3. The view that what we see around us is not real, and that our lives and everything we value is essentially 'unreal."

Epicurus built his physics — the atoms, the void, the swerve, the emergent properties of compound things — specifically to establish that the natural world we experience is self-sufficient and self-explanatory. Nothing comes from nothing; nothing goes to nothing; the universe operates by natural processes, not divine whim or iron destiny. That framework is what allows the ethics to work. Pull out the physics, and you immediately create space for the supernatural to rush back in — which is exactly what Epicurus' rivals (Plato, the Stoics, and later the Christians) did with great success.

Now, as to the Sedley article specifically — and the question of whether Epicurus was a "reductionist" — this turns out to be very relevant to modern Epicurean life, more than it might first appear. Sedley's argument is that Epicurus was not a strict reductionist: he did not say that your feelings of pleasure and pain, your lived experience, your psychological states are "mere illusions" that dissolve into atomic physics if you look closely enough. The qualities of compound things — including the pleasure and pain we feel — are real, not eliminable, and must be understood at their own level. That is philosophically powerful ammunition against the modern dismissal of Epicurean ethics as "merely subjective" or "just brain chemistry."

So the short answer to your question "why should I care about the atoms debate if so much science has changed?" is: care not because the technical atomic details are sacred, but because the method and framework Epicurus established — natural causation, no supernatural intervention, emergent reality at the level of lived experience — is exactly what you need to build and defend a life philosophy grounded in nature. And you need confidence in a framework that establishes that your life and the things you value are truly real. The details update as science advances; the framework remains as essential as it ever was.

The full updated FAQ answer is here:

Why Should I Care About Epicurean Physics When So Much Science Has Changed in the Last 2,000 Years? - Epicureanfriends.com

www.epicureanfriends.com

Dave, the answer to both of your questions seems to me to be pretty much the same. These things are not "totally subjective" nor are they "just brain chemistry." As the article is discussing, emergent properties like the mind's actions are not mechanically determined by atoms and void, nor are they totally subjectively under the power of the mind. Most people cannot through mental will power find buring their hands in a fire to be pleasurable - on the other hand did not the feeling of pleasure and pain work regularly across people, there would never be any regularity at all in what people find to be pleasurable or painful.

That's why this discussion is important. Epicurus is discussing the limits and boundaries of properties of atoms and the qualities that emerge from combinations of atoms. All of this directly refutes the idea that human life is either chaotic or determined supernaturally.

And in the end what we are doing is PHILOSOPHY - we are exploring a 'systematic study of nature' that allows us to have confidence that all of this is occurring naturally and without input from or direction from gods (if you're the religious type) or chaotically (if you're the nihilist type). I suspect that you are neither and that's why you think it's ok to go right to ethics, but Epicurus thought (and I do too) that the world in general is not that way, and that everyone from childhood needs to be taught a systematic approach to the way the world works that allows us to live successfully.

These are the issues we are really talking about and that Epicurus is addressing. Epicurus could care less whether we call fundamental particles atoms or protons or neurons or quarks or anything else, and I think if he were here today those who focus on that perspective are in fact lost and will never see the bigger picture until they back up and decide philosophically what "reality" really means.

Quote from DaveT

I think it would be a better course to maximize Epicurus’ reasons for his physics and minimize the study of the details for the average student, like me.

Probably that's the cruc of the issue. There's a wide variety of people here with different backgrounds and interests, but this is primarily a forum for the promotion of Epicurean philosophy, not for philosophy generalists (not placing you in that latter category).

I am working on how to better deal with people on the newer side but as I see it the primary need in Epicurean philosophy is not that of building bridges to people of different opinions but working to develop a core team of people who like me share the conviction that Epicurus is uniquely worth rebuilding a "team" or "camp" of those who want to approach modern problems from the perspective of actual ancient Epicureans.

In most respects other than pure technology I see mostly regression from 2000 years ago, and in order to deal with that regression we need to focus on where things went wrong and how applying core Epicurean attitudes could redress those problems.

There are plenty of places on the Internet where people can discuss raw hedonic calculus from generic point of view, but almost no one bringing to bear the insights that people like Dewitt and Sedley have written about over the last 50 years.

So I will work on both but that's the explanation for where we are.

These are very relevant points Dave and I think about them all the time. Here's my current view.

Quote from DaveT

On the other hand I see progress away from the monarchical God and church appointed governments of the last 250 years. No longer do we accept conquest in the name of god's command to subjugate the earth.

I don't think I am violating the no-politics rule by observing that the world is on the brink of WW3 and I would say that a major reason is that most of the world is still in the grip of religious and philosophical absolutism of the very kind that Epicurus was fighting against.

Quote from DaveT

I think there is something to be said about a focus on the secular adaptation of Epicurean principles that have made their way into common society, into academia and medicine as well as government policies even though those principles are not often recognized as Epicurean.

Unfortunately here too I am convinced that the darker side of this overwhelms the brighter. The "secular adaptation of Epicurean principles" is largely a bastardization of what Epicurus actually taught, and is in fact being used to suppress any reemergence of his actual teachings. I'll paraphrase someone I don't particularly admire and say that the most "common secular adaptations of Epicurean principles" - by which I mean the elevation the pursuit of immediate pleasure as a tranquilizer against deeper understanding of philosophical issues which undermine the word today as they did in 300 BC - are as much the opiate of the people as any religion.

Quote from DaveT

Most PEW polling shows the decline of popular participation in religious organizations.

I think you're talking about our "first world" situation primarily in the USA. Disturbingly even here I understand the evidence shows a resurgence in religious interest, particularly Catholicism, and of course I am not seeing that as a positive development. It's interesting to consider that in Catholicism we see preserved many of the same Platonic/Stoic positions that were incorporated directly into it. The early Catholic "church fathers" understood Epicurus to be strong opposition. I do think that a lot of the turmoil in organized religion presents an opportunity for the re-emergence of a true Epicureanism, but that re-emergence isn't going to be accomplish by a superficial understanding of Epicurus as a neo-Stoic / neo-Buddhist / Humanist who is running from philosophical and social engagement to live a minimalist / ascetic life.

Quote from DaveT

On your point of searching for a way to deal with newer people, I'm guessing you mean newer to the Forum. I've heard that the way to engage with others is to ask those people, who they are in real life, why they joined, what their goals are at the Forum, and perhaps when they might have the time to participate. I think those questions can be asked tactfully, not just to new people, but perhaps they might become a part of an annual discussion among the membership.

I largely agree with you here but there is a danger that I also constantly consider:

Until people understand what Epicurus was really all about, they are tempted to focus only on the surface ethical questions such as how to experience more pleasure than pain under a conventional outlook of focusing only on stimulative pleasure. There are also those who come here fully convinced that the goal of life is "tranquility" and the last thing they want to do is to face uncomfortable deeper questions. Posts from such people give us an excellent opportunity to educate them about the full meaning of the texts, but too much emphasis on "momentary pleasures" and "relief from anxiety" without understand that "relief from anxiety" does not mean a "zero state," but pleasure in the full and true meaning of the word, is difficult to deal with given existing resources.

We need more people actively writing about Epicurus from a more educated and deeper perspective, so I think the priority has to be "educating the educators" so we can better address exactly what you are talking about with people who are just beginning to read Epicurus.