Thursday, August 15, 2019

Discussion on Reductionism

This is a discussion on reductionism I had with another poster, @gquenot, on Biopolitics and Bionews, on a now disappeared thread.  I repost it here as I think it may be of interest.

Me:One of the heavyweights in philosophy of mind, Jaegwon Kim, considers the consensus of the last 5 decades of debate to be -- "qualia is not reducible to neurology". https://www.amazon.com/Phys... I have a review, which summarizes.

gquenot: Thanks for the reference and for the review that I found here. This is not a very positive review even though you rated the book 5-star.
It is difficult for me to appreciate whether or not or to what extent the consensus of the last 5 decades of debate really is “qualia is not reducible to neurology”. If, like Daniel Dennett, we think of qualia as “the ways things seem to us”, I see no obvious reason for which these should not be reducible to neurology (not claiming that they are, nor that they should be).

Me: Much philosophy writing is turgid and assumptions are unclear. And for even good thinkers— what fraction will one agree with? I run about 50% agreement with Kim and can clearly see what assumptions I disagree with for the rest. This deserves an A+ to my mind.
Non reduction? There are three primary reduction approaches: ignore mind (behaviorist and functionalists), eliminate mind (eliminativists), dismiss mind (delusionists). The leading functionalist, Putnam, has abandoned functionalism, and the leading eliminativist, Churchland, has abandoned eliminativism. Dennett has not abandoned delusionism, so at least one branch of mind denial is still active, but Kim considers Dennett to have lost the debate among his peers.
For those who accept mind, Kim considers inverted rainbow, Mary the color scientist and Chinese Room to be unrefuted arguments for irreducible qualia. He is not alone in this. The Stanford encyclopedia entry on scientific reductionism agrees the consensus view is that reduction is a failed project and irreducibility of mind is a prime example of this failure.


gquenot: 
[…] This deserves an A+ to my mind.
This makes sense.
[…] Kim considers Dennett to have lost the debate among his peers.
Possibly but I don’t see this as settled and there might still be other reductionist options.
[…] unrefuted arguments […]
I have almost never been convinced by a thought experiment. They are basically appeals to intuition. They may work with people sharing the appropriate intuitions but not with others.
The Stanford encyclopedia entry on scientific reductionism agrees the consensus view is that reduction is a failed project and irreducibility of mind is a prime example of this failure.
I will have a look. Such a bias seems strange from SEP. It may be that the reductionist view is a minority one but I don’t see it as a failed project at all, not that it has succeeded indeed but I don’t think that the question has been settled.

Me: Here is the intro to section 5:
The mainstream in the philosophy of mind is, apparently, one version or another of non-reductive physicalism. The majority within the philosophy of science has nowadays abandoned the unificationist program, to which reduction was intimately connected right from the start. However, as became apparent only in recent years, some questions regarding the concept of reduction have not successfully been accounted for yet, and recent developments in metaphysics in connection with metaphysical grounding may shed new light on the concept of reduction.
And the lead paragraph of 5.4:
Scientific reduction became an important topic in the philosophy of science within the context of a general interest in the unity of science, and it was inspired by specific alleged cases of successful reductions. The most prominent argument against reductionism stems from the observation that straightforward reductions hardly ever occur. Hence, reductionism cannot be regarded as yielding a coherent picture of what actually goes on in science. As long as reductionism is supposed to be more than a purely metaphysical position and is intended to say something significant about scientific change or norms, the value and relevance of the notion of reduction seems to depend in part upon how well the reductionist positions fit the facts, which their critics argue they do not (see, for example, Sarkar 1992; Scerri & McIntyre 1997).
I share your skepticism of thought problems, and consider empirical test cases more significant.

gquenot: I read the whole section 5.4. It may be a fact that most philosophers have abandoned the view of reduction as one of the core notions of theories defending one form or another of scientific unification. It is clear also that if something can “block the reductionist train in its track”, it must be the “mind problem”, with the consciousness and freedom questions specifically. However, those who say that it is impossible should not stop those who are doing it. In this respect, the article could have been a bit more neutral.
Regarding “more significant empirical test cases”, I strongly recommend: Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts by Stanislas Dehaene. This is not at all a philosophy book (I even think that Stanislas Dehaene carefully avoids to make any philosophical digression; he just temperately mentions in the beginning that his work is conducted in a naturalistic context) but I think that its contents is nonetheless highly relevant to the philosophy of mind. Indeed, progresses are being made on the neuroscience side but the problem is still far from being solved.

Me: When not all of physics reduces to QM and relativity, that is a problem for reductionism. When only about half of chemistry reduces to physics, and only biochemistry in biology, and this is the limit of reductions in science, then reductionism as a global claim is empirically untrue. That psychology does not reduce to biology -- is not an anomaly, and is an expected outcome of a non-reductive approach to science.
Insisting on a biologic reductionism approach for psychology, despite the global failures to date for reductionism, is pretty clearly ideological dogmatism. Seeing if one can somehow make it work when nobody else has before -- that is how science advances, so more power to anyone giving it a go.
But based on the failure of reductionism to date, science needs to be based on a non-reductive model -- and non-reductive theories of mind are where one is most likely to see success.
As for empiricism on this question -- Susan Blackmore did an excellent job compiling empirical data relative to mind theories: https://www.amazon.com/gp/c...

gquenot: We may have different intuitions on these questions and I see nothing wrong with that.
Which of insisting on or rejecting reductionism is more dogmatic seems quite subjective to me. I don’t see any reason for making any claim either way; we may just consider the question as unsettled yet and continue to explore both alternatives. I do not share your feeling on “the failure of reductionism to date” and I don’t see what a non-reductive model for science could be.
We may indeed think of “non-reductive theories of mind” but these can’t be scientific theories. Honestly also, I don’t see how one can explain anything (regarding its nature or its operation) with a non-reductive theory, be it scientific or not. Maybe an example?
Susan Blackmore’s book looks interesting and I plan to read it. However, Stanislas Dehaene is not someone that compiles empirical data relative to mind theories, he is among those that are producing these data. In this domain, his book is the best I have ever read.

Me: I have added Dehaene to my reading list. Thanks!
That failure to reduce, and valid theoretical reasons WHY reduction is impossible in principle across the sciences, is still insufficient to convince you that reductionism cannot work? I would submit that yours is by definition an anti-scientific position -- you reject the possibility of falsification , even when provided falsifications.
Here are two links that may be helpful in understanding non-reductive science:
Incommensurability across disciplines is intrinsic to science: https://www.academia.edu/87...
Reasons why reductionism was a default assumption, and is no longer valid, focusing on downward causation:
http://web.missouri.edu/~se...

gquenot: 
That failure to reduce, and valid theoretical reasons WHY reduction is impossible in principle across the sciences, is still insufficient to convince you that reductionism cannot work?
Failure to reduce? Failed attempts so far or current “gaps” are just that, they do not prove that reductionism cannot work.
Valid theoretical reasons? I honestly don’t see what you are referring to.
In both cases, what would constitute a successful reduction is not that clear and the in principle possibility of and the actual realization of a reduction are two different things. To be a bit more specific on that, no biologist pretends that it is practically possible to explain the functioning of a particular organ, say a heart, directly in terms of quarks and electrons. Yet, whatever philosophers might in majority think about that, the vast majority of biologists (I don’t even know of a single exception) really believe that the nature and functioning of a heart is “quarks and electrons interacting through fields”, that and nothing else but that, however intractable that might turn out to be in practice. The consensus might be lower and possibly much lower when it comes to mental-related things but, apart from that, from geology to biology, the vast majority of scientists do consider that everything is reducible to “particle physics” in the sense that nothing else needs to exist or to intervene and, even more, that postulating such something else does not help to explain anything more in any discipline.
non-reductive science
I will have a closer look but this mostly seems to address practical difficulties, it does not seem to invalidate the possibility of reductionism itself. Also, I don’t see how the observation of a lack of practical unification or of practical unifyability deserves to be called “non-reductive science”. At best, this could be called “non-unified (yet) science”. The real question is: what more can you expect to explain by postulating a non-reducibility and how?

Me:  This review states that reductionism among biologists is, contrary to your claims, a minority, shrinking, and almost disappeared, view: https://scienceblogs.com/wo...
Do you need citations to show that psychologists, sociologists, economists, etc are also not reductionists? In asserting reduction is necessary you are in conflict with the experts in the fields in question.
One of the links I provided note that incommensurality of different sciences -- IE their terms and metrics are fundamentally untranslatable. The second noted the emergence of structures which are not reducible to substrates, and downward causation. all three of these are incompatible with reduction. These provide a theory as to why reduction fails.
Meanwhile, efforts to implement reductionism have failed dramatically across almost all of science. Note, failed predictions are falsifications. And a wholesale collection of failures is basically the definition of a failed research programme: http://people.loyno.edu/~fo...
The instance on reduction contrary to expert consensus, in conflict with apparent theoretical impossibility, and despite the hypothesis being falsified by both Popperian and Lakatian standards -- is pretty dramatic ideological dogmatism.
Meanwhile, this claim:
apart from that, from geology to biology, the vast majority of scientists do consider that everything is reducible to “particle physics” in the sense that nothing else needs to exist or to intervene and, even more, that postulating such something else does not help to explain anything more in any discipline.

if you really are asserting that the vast majority of scientists are reductionists on everything but consciousness -- is both unsupported and pretty dramatically untrue.


gquenot: 
This review states that reductionism among biologists is, contrary to your claims, a minority, shrinking, and almost disappeared, view: https://disq.us/url?url=htt...
This review states that reductionism is possibly a minority view among philosophers of biology. It says nothing about how widely this view is shared among biologists. I am still waiting to see a biologist claiming that there must be something else than particle physics for explaining the functioning of a heart, even if none is directly doing that and even if they routinely work at higher (and approximate and simplified) abstraction levels.
Regarding social sciences and economics, one can argue that they do include some psychological components, even if not explicitly so the consensus might be lower there too.
In practice, many scientists possibly do science only within their own discipline with little attention to “the big picture” and without necessarily caring a lot about the questions that interest philosophers. Yet, within “hard” sciences (say excluding psychology and anything depending upon it), I still believe that no or very little scientists consider that something else that particle physics must intervene for explaining what happens in their discipline, even if particle physics in not the most efficient level for them to work with (and that might be a euphemism).
I would like to see an example of something that would be definitely incommensurable or untranslatable between biology and physics and/or what that would actually mean and how this would rule out a possibility of reductionism.
Same for “the emergence of structures which are not reducible to substrates”.
Regarding “downward causation”, I see that as more a problem for non-reductionist approaches than for reductionist ones and this involves mental stuff and therefore leads to a lower consensus too.
Again, failed attempts so far are just failed attempts so far and do not prove anything.
Dogmatism is in saying that an issue has been settled, not in saying that it is still open. I am not saying that reductionism is true or must be true (or achievable), just that it has not been ruled out yet.
if you really are asserting that the vast majority of scientists are reductionists on everything but consciousness -- is both unsupported and pretty dramatically untrue.
Maybe the confusions comes from the fact that I am talking of scientists while you are taking of philosophers of science.

Me:  gquenot -- your reply comes across as fundamentally dishonest.
This review states that reductionism is possibly a minority view among philosophers of biology. It says nothing about how widely this view is shared among biologists.
Reductionism is a philosophy question -- specifically philosophy of science. Non-philosophically oriented biologists would have no insight into this question. And philosophers of science have always been a mix of scientifically oriented philosophers, and philosophically oriented scientists, so any consensus among philosophers of biology will by definition include multiple biologists.
Also, despite several requests from me, you have provided NO support for your repeated claims of what biologists think.
that there must be something else than particle physics for explaining the functioning of a heart, even if none is directly doing that and even if they routinely work at higher (and approximate and simplified) abstraction levels.
NO explanation from ANY biologist for the operation of a heart references particle physics!
Regarding social sciences and economics, one can argue that they do include some psychological components
"include some psychological components" is explicitly =/= reductionism to psychology. For problems in a different field to be interactive with and usefully informed by another science is -- SOP in science, and has nothing to do with reductionism.
I still believe that no or very little scientists consider that something else that particle physics must intervene
You continue to equate physicalism with reductionism. Physicalists can be, and primarily are, non-reductive physicalists. Supervenience is not reduction (although Kim correctly points out that to avoid reduction through supervenience, emergent structures must be causally independent of their substrates).
I would like to see an example of something that would be definitely incommensurable or untranslatable between biology and physics
Species. Symbiosis. Parasitism. Population. Ecosystem.
You appear not to have put any thought whatsoever into looking for challenges to reduction, despite my spoon feeding you multiple references, and specifying the consensus view of science today.
Again, failed attempts so far are just failed attempts so far and do not prove anything.
Dogmatism is in saying that an issue has been settled, not in saying that it is still open. I am not saying that reductionism is true or must be true (or achievable), just that it has not been ruled out yet.
We deal with our world empirically, and science is an empirical discipline. It cannot provide "proof". Science operates off failed tests, from which we reject the hypotheses that failed these tests. I showed how these failures satisfy both the Popperian and Latakian standard for rejecting reduction.
I repeatedly encounter ideological dogmatists, be they religious, political, or philosophical like yourself, who insist on holding by their ideology until it is definitively refuted. For an empirical question, this is an impossible standard to meet, so your rationale is an explicit fallacy. It is also an overt rejection of science, which I pointed out to you many many posts back.
Maybe the confusions comes from the fact that I am talking of scientists while you are taking of philosophers of science.
I don't believe there is actually any confusion. You admit in this very post that "most scientists" don't think about, and have no clue on, this philosophical question. I have cited the scientists who do pay attention, who are among the community of philosophy of science. You simply refuse to accept what the philosophic/science experts say.


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