What do you call the fact that you can't derive all the laws of other sciences from the law of physics? Is there a word or a term or something else that explains why this is the case? I would be interested if there ever was a philosophical discussion on this.

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    Are you referring to the claim that this isn't possible even in principle (a controversial idea sometimes called strong emergentism), or just to the fact that we can't usually do it in practice because it's too difficult to determine the precise initial conditions of a complex system and too difficult computationally to calculate what the fundamental laws of physics would predict about its dynamical behavior given those initial conditions?
    – Hypnosifl
    Apr 28, 2021 at 2:21
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    We don't find meaning or intention in physics descriptions either. I would look to heurustic explanatory overlays, with narrative units pictured as supervenient for utility. Discussed in more detail in relation to free will here: philosophy.stackexchange.com/questions/77330/…
    – CriglCragl
    Apr 28, 2021 at 12:20

4 Answers 4


Your description sounds like anti-reductionism:

Antireductionism is the position in science and metaphysics that stands in contrast to reductionism (anti-holism) by advocating that not all properties of a system can be explained in terms of its constituent parts and their interactions.

Karl Popper was a famous proponent of antireductionism. In his essay Of clouds and clocks, Popper classified phenomena into two types: "clock" phenomena with a mechanical basis and "cloud" phenomena which are indivisible and depend upon emergence for explanation.

For example, Popper thought that a materialist explanation of consciousness is not possible. The view of reductionists about consciousness is explained by Max Velmans:

"Most reductionists accept that consciousness seems to be different from brain states (or functions) but claim that science will discover it to be nothing more than a state or function of the brain. In short, they mostly accept that brains states and conscious states are conceivably different, but deny that they are actually different (in the universe we happen to inhabit)."

As for some other philosophical arguments for anti-reductionsim:

physicist and philosopher Thomas Kuhn hold that science is not a self-contained entity, because the theories it uses are creations of the human mind, not inevitable results of experiment and observation, and the criteria for adoption of a particular theory are not definitive in selecting between alternatives, but require subjective input.

Also Leibniz once emphasized self-consciousness cannot be reduced to mechanics governing extended matter from his famous mill argument.

  • The question seems to be about reductionism in the sense of higher-level empirically verifiable laws being reduced to fundamental physics, whereas issues relating to consciousness may be about some more metaphysical notion of reduction. David Chalmers would be an example of a philosopher who accepts the likely truth of reductionism in the first sense (he thinks all empirically measurable behavior probably can be derived from fundamental laws of physics) but thinks conscious experience is metaphysically distinct from brain processes so he's "anti-reductionist" in the latter sense.
    – Hypnosifl
    Apr 28, 2021 at 14:16
  • @Hypnosifl thx for ur comment. I'm not sure whether OP's sciences category includes mind and consciousness areas either. I agree with your summary and classification generally. But if Kuhn's opposition to reductionism above holds and math is a construct of mind, then seems physical laws could be reduced further to math (mind), this was one of bases for rationalism fight back towards logical empiricism later last century. Apr 28, 2021 at 17:05
  • I agree. I immediately thought “anti-reductionism”. Apr 28, 2021 at 20:34

The term you are looking for is "Pluralism". It is the thesis that the Reductionist dream of the unity of sciences (and of reduction of everything else to science, in the scientism version of this dream), has and will forever continue to fail.

Pluralism is currently the majority view of the philosophers of science -- that the other fields of science are not and never will be reducible to physics. See the final section of the SEP entry: https://plato.stanford.edu/entries/scientific-reduction/

There is theory behind pluralism -- that when the key concepts and features of a field are simply disconnected from the lower level science field, then they will never be reducible to it. For instance, cells are not reducible to molecules or atoms -- molecules change radically over time in cells, and atoms drift in and out of them -- a molecular or atomic reductionism simply cannot ever work, because it focuses on the wrong (and irrelevant) questions. An atomic focus simply cannot be relevant to cellular function, cellular health, etc.

  • "For instance, cells are not reducible to molecules or atoms -- molecules change radically over time in cells, and atoms drift in and out of them" Why is that an argument against reducibility? In computational chemistry there has been plenty of progress in showing how molecular behavior (including molecular changes) can be recreated in simulations which use only the laws of physics without additional laws of chemistry, is there any reason you think with greater computational power it would be impossible to do the same thing for DNA or even cells, including atoms drifting in and out etc.?
    – Hypnosifl
    Apr 29, 2021 at 3:00
  • The current majority view is that reduction fails, and will automatically fail, when there is a radical disconnect between the parameters of relevance in a higher level science and the parameters of the lower level science. This view has been developed by observing the failure of reductionism in field after field, and characterizing what is common about those failures. This is the scientific inductive process, which is always a judgment call. The majority of philosophers of science today have been convinced that the pattern of failure reveals a truth about our universe.
    – Dcleve
    Apr 29, 2021 at 3:08
  • @Hypnosifl Theory always is underdetermined by evidence, so one can always hold on to the hope that someday some exception/explanation/surprise-discovery will provide evidence to support one's preferred view. But then, even if you get the evidence you hope for, any equally dedicated opponent can then hold onto the inverse hope. This hope is not irrational, but it is counter to the science process, which endorses inference based on actual observation and model fitting.
    – Dcleve
    Apr 29, 2021 at 3:12
  • But are you talking about reduction as a practical matter where scientists dispense with the higher level theory and just use the lower, or are you claiming there's reason to disbelieve in reduction in principle, that if we could measure the detailed quantum state of a complex system and simulate its behavior using just the laws of physics, we would reproduce the higher level behavior? Most scientists would take the latter as a default assumption but agree it would be too computationally difficult in practice, and there would be reasons to use higher level simplified models even if we could.
    – Hypnosifl
    Apr 29, 2021 at 10:00
  • Your "most scientists believe" claim is not true. The majority of biologists think their field is not reducible to chemistry IN PRINCIPLE. Same with psychologists to neuroscience, sociologists to psychology, etc. When reduction has failed to be complete for all of physics, and applies to only about half of chemistry -- the inference from the early successes of reductionism for most of physics and half of chemistry, and some of biology, that it could be a universal principle, has been shown by failure to be an unsupported extrapolation. You can of course continue to believe it anyway...
    – Dcleve
    Apr 29, 2021 at 16:30

It might just be unfinished work.

Consider this passage in the SEP:

"Consider classical mechanics first. The observables are functions on phase space, functions of the positions and momenta of the particles. The axioms governing the behavior of the basic observables—Newton’s equations for the positions or Hamilton’s for positions and momenta—define the theory. What would be the point of making additional axioms, for other observables? After all, the behavior of the basic observables entirely determines the behavior of any observable. For example, for classical mechanics, the principle of the conservation of energy is a theorem, not an axiom" https://plato.stanford.edu/entries/qm-bohm/

It is saying that empirical observations are made through observations of physical quantities - observables. And just two observables, position and momentum, entirely determine the behavior of every other observable when taken along with some basic axioms governing the two basic observables (e.g. Newton's or Hamilton's laws).

We don't need any extra rules to tell us what will be observable/possible. That's the beauty. We can add extra theorems like the conservation of energy, to simplify things for us, but they are not adding additional necessary info.

To take the above to its logical conclusion, we simply have not developed intermediate theorems between observables from other sciences and the base observables of position and momentum. The logical conclusion in this line of thinking is that some theorem or theorems exist uniting the two layers, we just haven't been smart enough or had enough time to develop them.

There is probably a more concise term for this frame of view.

  • Hmm -- what YOU just described is the inverse of what the questioner asked for. You just stated an unfalsifiable faith in the necessity of thorough an universal reductionism always being true. And a rejection of any evidence to the contrary as being "incomplete". Note that, for ANY evidence in science, Quine noted one can ALWAYS postulate some as yet undiscovered mechanism by which it might not decisively show what it appears to show (theory is always underdetermined by evidence). But SCIENTISTS do not accept these wild speculative possibilities as relevant, and use the data they have.
    – Dcleve
    May 3, 2021 at 2:53
  • And the data is that despite tremendous early successes, and clear utility as an investigatory method -- reduction has failed in cases of phase change, chaos, and tiers of emergent phenomena. Not all of physics appears to be reducible, only about half of chemistry, and only the biochemistry aspects of biology -- it has not worked for pretty much any other science. The inference that reduction is universal, has been tested, and it failed those tests. Now maybe, like with ALL science conclusions, later insights might overturn this. But scientists run with the data they have now.
    – Dcleve
    May 3, 2021 at 2:57
  • @Dcleve I didn't answer the inverse - I gave a possible reason why we can't derive all laws from a smaller subset - that we lack the ability in practice, not in principle.
    – J Kusin
    May 3, 2021 at 9:19
  • The only thing that science has come close to empirically "proving" is not reducible is the quantum wave function. I strongly suspect you are conflating gaps in scientific knowledge with failure of reduction. Phase changes, chaos, and emergence are hardly evidence against reduction, if at all. Chaos doesn't mean in-principle unpredictable, and it is a feature of reduction to have multiple explanatory layers (e.g. emergence). It does seem like reduction ultimately fails at the quantum wave function level, but certainly I am not convinced in calling a lack of bridge laws as the end of reduction
    – J Kusin
    May 3, 2021 at 10:02
  • Reductionists predicted that their methodology would lead to the reduction of all of physics to QM, and the rest of science to physics. There was tremendous progress made in these tasks for several decades, and this was taken as evidence supporting universal reduction. That progress has stalled out at ~90% of physics, 50% of chemistry, just a portion of biochemistry, and a usefully suggestive methodology in the rest of science -- but actual reduction outside those bounds -- has been unsuccessful for nearly half a century. Over that time our processing capability has increased by ~6 OOM.
    – Dcleve
    May 3, 2021 at 16:05

The position that the laws of one branch of science can be deduced from another branch is called reductionism.* The two simplest counter-arguments are the Many-One Argument and the One-Many Argument.

Many-One Argument
This is the argument that many 'fundamental' phenomena corresponds to one 'derived' phenomena. An example is albinism. There are 4 types of albinism conveniently named type 1, type 2, type 3, and type 4. Type 2 and 4 have the same symptoms even though they caused by different genes (OCA2 and SLC45A2, respectfully).

One-Many Argument
This is the argument that one 'fundamental' phenomena corresponds to multiple 'derived' phenomena. An example is exons, introns, and alternative splicing.

A single gene can contain numerous exons and introns, and the exons can be spliced together in different ways. For example, if a gene contains 10 exons, one version of the mRNA transcribed from that gene might contain exons 1-9. Another version of the mRNA might contain exons 1-8, and exon 10. This is called alternative splicing, and can produce different forms of a protein from the same gene. The different forms of the mRNA are called transcript variants, splice variants, or isoforms.

*Be careful looking into this. Scientific reductionism is an extremely different topic than reductionism in science

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