8

Classical Greek atomism arose basically as a response to the Eleatic criticism of the concept of change. The Eleatic argument was basically that if X=Y, then all properties of X must also be properties of Y, but if X is a thing at one time and Y is the same thing at a later time after the thing has changed, then X and Y don't have the same properties, so they aren't the same thing any more. Note that this is an essentialist position: X has an essential identity and it is that essential identity that cannot change.

Aristotle's solution to this problem involved distinguishing between essential and accidental properties. The atomist solution to this problem was to postulate that everything is made up of atoms, so the things of sense perception are aggregates of atoms and have no essential properties of their own. However, the atomists were still essentialists; they just pushed the essential properties down to the atoms. The atoms had essential, never-changing properties and had no parts of their own. However, this is not satisfying, because no matter how small the atoms are, you can always imagine geometrically dividing them up into parts, so the fact that they can't come apart seems more associated with the strength of the force holding them together than to a metaphysical simplicity. "Simple" means having no parts.

Does modern physicalism have the same issue? They can either appeal to subatomic particles as having no parts and having essential unchanging properties, or they can admit the existence of parts. If they think there are base particles with essential unchanging properties, then they are basically saying that science has reached its limit; there are these things in the universe that science is unable to analyze; all it can do is discover how it behaves. If they admit the existence of parts, then they are in danger of an infinite regress of parts of parts. This is a problem for physicalism because the point of physicalism is that the smaller explains the larger. You explain the behavior of a planet by explaining the behavior of the particles that make it up. If there is an infinite regress of parts, then there is no ultimate explanation of anything.

There are various evasions the physicalist can try. They can, for example, say that the basic units of the physical world are not particles but fields, but that really doesn't solve the problem. Are these fields compound objects or simple? If simple, then science has once again reached an arbitrary limit in what it can investigate. If complex, then once again there is the danger of an infinite regress.

My sense is that physicalists would not accept an infinite regress, so they seem to be committed to some layer of the universe that is metaphysically simple, that has essential properties, and that cannot be analyzed further by science.

David Gudeman
  • 6,647
  • 1
  • 10
  • 38
  • I agree a final theory of physics would involve a limit beyond which there would be no further answers (why those ultimate laws and not some others), but metaphysically this needn't involve substance metaphysics and essentialism--one could also interpret the ultimate laws in terms of a [structural realist](https://plato.stanford.edu/entries/structural-realism/) metaphysics in which each particle (or other primitives, like 'events') is wholly defined by its mathematical relations to other particles/events. See Steven French's *The Structure of the World* or Ladyman/Ross *Every Thing Must Go*. – Hypnosifl Sep 15 '22 at 20:15
  • No. This analysis presupposes *classical* objects at the "ultimate" level, with their relation to properties and parts that is obsolete. Elementary (*quantum*) "particles" have no parts, but still morph into each other in collisions, so they are "simple" structurally, but not behaviorally. More particles appear at higher energy levels, so interactional behavior of *any* "simple" particle is potentially inexhaustible. Neither physicists no physicalists are deterred by epistemic infinite regress this entails, infinite towers of "effective" theories with no "ultimate" theory are easily envisioned – Conifold Sep 15 '22 at 21:21
  • @Conifold, I pointed out that even if you have some other notion of what particles are, then either they have parts or they don't. You suggest that they don't have parts, but they do have properties. If a thing is perfectly simple but has properties, then it must have essential properties. That is, it must have properties such that it can't be what it is without those properties, and where those properties cannot be explained by its composition and configuration. Also, the regress I was talking about is not epistemic but causal. – David Gudeman Sep 15 '22 at 23:42
  • Sure, quantum particles have properties, we can even call some essential. But they are not unchanging, electrons get annihilated by positrons with photons emitted, and those are equally "simple". Your examples of "smaller explains larger" are all classical mechanistic ones, physics abandoned this mode of explanation since the fall of aether. Why is "analyzing" supposed to be breaking up into parts rather than modeling morphing behavior? How is discovering "smaller parts" saliently different from discovering "how it behaves" when refining models? And how does explanatory regress become causal? – Conifold Sep 16 '22 at 01:07
  • 1
    I'm having difficulty seeing what’s essential in inflationary multiverse theories, where entire universes can be devoid of particles or similar degenerate cases. Another problem is that these multiverses are sometimes brought in to explain things, such as Susskind does to argue why we don’t observe Boltzmann brains. Hardly simples doing the explanatory or causal legwork. Maybe there's one multiverse wide field, but you need to sum over the entire multiverse to explain some things, like why BB's are rare, why time only goes forward, like here https://youtu.be/jhnKBKZvb_U?t=2940 (Susskind) – J Kusin Sep 16 '22 at 16:11
  • "the point of physicalism is that the smaller explains the larger" No. That's reductionism, not physicalism. Emergent properties are perfectly compatible with physicalism, and non-reductionist. – CriglCragl Sep 16 '22 at 19:09
  • Essentialism is diametrically opposed to existentialism not physicalism, idealists such as Plato are well-known essentialists who believe there's such an essential/ideal difference between cat and dog that one can meaningfully ask *what's a cat and what's a dog?*... – Double Knot Sep 17 '22 at 21:01

1 Answers1

2

This question has some understandable confusion between science and physicalism, and also about what relation essentialism has to science.

Science is based on the principle that our world is contingent, and discovering its features requires investigation, rather than reasoning. Whether that investigation will ever terminate, is left as a TBD by science. Note, there are three possible resolutions of Munchausens's Trilemma, and circularity is a third alternative to your infinite regress and unexplained brute fact. If elementary particles are unexplained -- IE we never discover a reason for the features of Standard Model of Quantum Mechanics, or for the non-integrated Theory of General Relativity -- that may be a possible termination of physics.

Note, science in general has adopted emergent pluralism as its primary ontologic view of itself. See section 5 of the SEP on scientific reduction: https://plato.stanford.edu/entries/scientific-reduction/ This pluralism extends to non-science as well, where the consensus view in and outside science, is that scientism's clam that science is the only valid source of knowledge about the world, is overwhelmingly false.

Physicalism is not an essentialist view. It has been adopted as a next best alternative by the materialists when the essentialist "materialism" of the 19th century was refuted by modern physics showing that "matter" wasn't fundamental to physics. Despite its widespread adoption within the philosophic community, physicalists themselves have had a great deal of difficulty even characterizing what physicalism IS.

This is because when originally adopted, physicalism presumed scientism, and scientific reductionism. With the widespread rejection of both premises, physicalism has come somewhat unmoored as a worldview. Hempel's Dilemma highlights this -- Hempel noted one cannot define physics or physicalism in a way that has testable (Popperian) content, and excludes the things that physicalists want to exclude (causal consciousness), and is not false.

Here are four good recent references on physicalism that exemplify its current problems. The links go to my reviews for the first 3. https://www.amazon.com/gp/customer-reviews/R13R2OUNXMIN6H/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=0415452635, https://www.amazon.com/gp/customer-reviews/R1LFTMUSP8VEWB/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=0691113750, https://www.amazon.com/gp/customer-reviews/R1A8I0RTYJEDJM/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=0521827116, https://www.academia.edu/819823/The_Rise_of_Physicalism

Note that of the four authors, two abandoned physicalism as a result of their exploration of the subject, and all four accept the reality of abstract objects (IE reject that everything is physical).

Physicalists today, unlike the first three authors, primarily are emergent physicalists. They accept pluralism in science and the universe, so believe that emergent phenomena are "real". Where emergent physicalists diverge from pluralism, is they hold that somehow physics is MORE real than any other subject area. How one arrives at this conclusion epistemologically -- is unclear to me. Science operates on indirect realism, where well supported hypotheses are presumed to be real, and there is no mechanism in this method for a more vs less "real".

A further presumption of physicalism is causal closure of physics. This is an assumption -- that when science is done characterizing the world, that there will be no causation needed from any emergent or pluralist phenomena -- IE explicitly from abstract objects, or from consciousness (or from anything spiritual, if science discovers the spiritual) -- onto physics. Note, this causal closure assumption -- is SPECULATION, and is actually in conflict with strong emergence, and with non-science pluralism, and with the recent inclinations of theoretical physicists, many of whom consider math to be causal of physics.

Repeating the answer to your question --while these physicalist assumptions may be questionable, they are not ESSENTIALISM.

Dcleve
  • 9,612
  • 1
  • 11
  • 44
  • I really appreciate an up to date rendering of physicalism. The SEP page on it completely abdicates on defining it. +1 – J Kusin Sep 16 '22 at 16:20
  • Very useful and informative, thank you. I didn't know that many physicalists had given up on scientific reductionism; my question was about the physicalism that does assume scientific reductionism (maybe the question should have been about scientific reductionism instead of physicalism). In that form, my question is still unanswered: "they seem to be committed to some layer of the universe that is metaphysically simple, that has essential properties, and that cannot be analyzed further by science". Is that correct or am I missing something? – David Gudeman Sep 16 '22 at 17:13
  • 2
    "Note, science in general has adopted emergent pluralism as its primary ontologic view of itself." Do you mean that philosophers have mostly adopted this view? Nearly every prominent natural scientists I've seen commenting on reductionism, whether in physics or biology, has endorsed the basic idea that all physical behavior is likely to be *in principle* derivable from physics alone, even if they don't endorse other forms of reductionism like methodological reductionism or ontological reductionism. – Hypnosifl Sep 16 '22 at 18:33
  • @Hypnosifl -- The SEP article was describing the views of philosophers of science. For scientists themselves -- you say you know biologists and physicists? Physicists may like the idea that they are the only science that studies "real" reality, but in my experience, most other scientists consider physicists to be a bit too full of themselves, and a inappropriately dismissive of the independence of the other sciences. For biologists, do you know NON-biochemists? Biochemistry is the only sub-field of any science other than chemistry where reductionism has had much success. – Dcleve Sep 17 '22 at 12:37
  • @Hypnosifl -- Further, do the biologists you know happen to be Neuroscientists? Neuroscience is the only field of science I know of today where total reductionism is still the dominant worldview. This is a bit of a historical anomaly, as Francis Crick, a devoted eliminative reductionist, successfully set out to recruit a generation of Neuroscientists with a similar mindset. The Wiki article on neuroscience notes, however, that in the most recent decade, NON-reductionist approaches have finally entered neuroscience as well, likely due to the failures there for pure reduction. – Dcleve Sep 17 '22 at 12:46
  • @JKusin -- The best "definition" of physicalism is implicit in Papineau's "The Rise of Physicalism". He basically treats physicalism as a Lakatosian Research Programme, a particular bundle of assumptions and approaches, which proved to be highly effective at addressing numerous problems in philosophy. His rationale for its rise among philosophers, uses Lakatos's thinking. So -- physicalism is a Research Programme, which for most of the 20th century was highly progressive. I like Papineau's thinking here, and extend it to today. continued – Dcleve Sep 17 '22 at 12:59
  • @JKusin -- The last decade or two of the twentieth century, plus the first few of the 21st, as my links note, have seen science abandon the global reductionist view, in favor of a combo of reduction, wholism and emergence. Plus a widespread recognition that the reduction of consciousness to matter, OR functions has failed. Add the now widespread acceptance of the reality of abstract objects, and the inclination of many theoretical physicists toward reducing physics itself to math, and there are an increasing, rather than decreasing list of "problem sets" for physicalism. – Dcleve Sep 17 '22 at 13:10
  • As I noted, physicalists themselves now have trouble identifying what it is today -- as it original incarnation and attraction WAS the assumption of global reduction of everything in the universe to physics. Add defining physicalism, and defending causal closure against physics which does not presume global closure, and physicalism is looking like a REGRESSIVE research programme. This explains why there is a decline in self identified physicalists in the philosophy surveys, and a rise in idealists, dualists, and "other". – Dcleve Sep 17 '22 at 13:15
  • @DavidGudeman -- No, reductive physicalism (RP) has tied itself to physics, which treats our universe and its features as contingent. RP DOES assume that when science is done, it will not have discovered any kind of thing exists that one needs fields other than physics to study -- IE no abstract objects, conscious will, strong emergence, art, or wholism. Physics today has already shown that elementary particles are not the base blocks of physics -- and for most of the last century have worked with the time-space continuum of Einstein, and the constants and symmetries of QM's Standard Model. – Dcleve Sep 17 '22 at 13:24
  • @Decleve, I'm confused by your repeated reference to the contingency of the universe as if that were inconsistent with the existence of essential properties. If there are a myriad of possible particles with essential properties, then which particles actually exist can be contingent. And of course, the distribution of those particles can be contingent. – David Gudeman Sep 17 '22 at 14:42
  • @Dcleve "most other scientists consider physicists to be a bit too full of themselves, and a inappropriately dismissive of the independence of the other sciences" But are you making a clear distinction between *methodological* independence vs. strong emergentism, the idea that the behavior of some complex systems is not even in principle derivable from physics? It seems to me that when many scientists criticize physics types approaches to their own field, their criticisms are about importing aspects of the methodology of physics. – Hypnosifl Sep 19 '22 at 18:01
  • For example, see Stephen Jay Gould's piece discussing Schrodinger's book "What is life?" [here](http://faculty.washington.edu/lynnhank/Contingency.pdf) (you have to rotate all the pages to the left in a PDF viewer). Here it does seem that his criticisms of reductionism and physics-think are methodological--he doesn't think biologists should see downplay the importance of contingency as physicists do, doesn't think biologists should focus on grand unified theories of biology as opposed to more pluralistic explanation, doesn't favor conceptual reductions like genetic determinism, etc. – Hypnosifl Sep 19 '22 at 18:04
  • But none of this really touches on the question of whether the behavior of biological systems is in principle derivable in some extremely complex (and perhaps useless methodologically for biologists) calculations of physical laws acting on initial configurations of particles. In [this interview](https://blogs.scientificamerican.com/cross-check/stephen-jay-gould-on-marx-kuhn-and-punk-meek/) Gould seems to support some version of reductionism with "I'm an old-fashioned materialist. I think the mind arises from the complexities of neural organization, which we don't really understand very well." – Hypnosifl Sep 19 '22 at 18:07
  • "The Wiki article on neuroscience notes, however, that in the most recent decade, NON-reductionist approaches have finally entered neuroscience as well" What quote in the wiki are you referring to? Again are you sure you aren't just talking about a non-reductionist methodology, which need not conflict with in-principle reduction of all behavior to physics? More broadly, when you earlier said "science in general has adopted emergent pluralism" were you talking about pluralistic methodology or about a belief in strong emergentism? – Hypnosifl Sep 19 '22 at 18:11
  • If you were talking about strong emergentism--the idea that the behavior of some large systems isn't even in principle reducible to consequences of physics acting on prior states--then what fields did you mean by "science in general", if you are excluding physics and large swaths of biology such as neuroscience and biochemistry? Are you claiming there is major support for strong emergentism in non-biological fields like chemistry, geology and astronomy, or are you exclusively making a claim about certain parts of biology, perhaps also including the 'human sciences' like sociology? – Hypnosifl Sep 19 '22 at 18:13