It seems to me that materialism can cover idealism, but not the contrary.

A materialist can recognize that reality is in part made of ideas, simply by saying that ideas are made of a bunch of materialistic entities, and circulate via a bunch of materialistic entities.

But this is not the case of idealism. Idealism can not recognize materialism.

Is this reasoning correct?

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    Perhaps give some background of what motivates the question. What are you looking for?
    – Scott Rowe
    Commented Jul 22, 2023 at 14:05
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    It's the other way around. Materialism cannot account for non-material ideas, but idealism can easily account for the material world. Commented Jul 22, 2023 at 17:16
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    Presumably, either can cover the other, but not in the same category of being. To avoid unnecessary confusion, note that each has both a noumenal aspect and a phenomenal aspect. One option is materialism (noumenon) contains brain contains consciousness contains idealism (phenomenon). Another option is idealism (noumenon) roughly equals or contains consciousness contains materialism (phenomenon).
    – Michael
    Commented Jul 22, 2023 at 17:20
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    The generalized concept of "physical" or "material" beings can be seen as idealized already, unless the concept of the physical is set opposite of the ideal. For example, Aristotle's definition of substance involves treating the physical world as composed of subject-predicate relations regardless of contingent language, with pure subjects = substance, a seemingly idealistic definition, but applied comprehensively to empirical nature. But when pure idealism can't cover matter, it's because of matter defined opposite non-matter, which leaves pure materialism not covering idealism either. Commented Jul 22, 2023 at 17:59
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    @armand, no, it is not inconsistent. It is not even odd. It would be a perfectly fine philosophical point even if your assumption were true and "materialism" did imply that the thing does not exist because if it did, my point would still be true. But materialism implies no such thing. In fact, most materialists believe that minds and mental phenomena do exist; they just think they are reducible to material things. But they have no idea how such a reduction might work, and so they cannot account for it. Commented Sep 29, 2023 at 8:47

4 Answers 4


Using your terms, idealism can "cover" materialism.

Picture a video game. Inside the game, physical objects are simulated by calculating what their interactions should be according to a set of mathematical rules. The physics of the simulated world are created by the consistent application of the rules.

The computer, of course, is itself physical, and it creates the simulation physically. But a sufficiently strong intellect could create a "physical" universe mentally just by imagining the objects in it, and making them interact according to consistent laws.

You can even do this yourself, at a much more modest scale. Just imagine a ball bouncing on the ground, and gradually coming to rest. You just created a very small physical universe, mentally.


Corroborating Dcleve's rightly-headed answer I want to make a fine but significant correction that physicalism can't even in principle account for mind and consciousness for reasons already explored or alluded to in literature on "the hard problem of consciousness", that I briefly summarize here.

Eliminativism somehow pretends something that is there is not there by assuming that consciousness is identical with some brain state or an illusion. But...

Identity theories provide no argument but only assert correlations to be identities, that is, phenomenally distinct data (of neuroscience and of conscious experience) are not actually distinct but the same, which is of course question begging, in addition to contradicting the logical principle of identity of indiscernibles and its opposite non-identity of discernibles.

Illusionist accounts, as I have explained and sustained it elsewhere, lead to logical contradiction, which is due to their mistaking consciousness (for which correspondence is meaningless, and which is rather the ground of all correspondence) with its particular states that can be true or false via correspondence.

Representationalism assumes representations are somehow possible without consciousness which is clearly not, for you can have no representation without being first conscious because all representations occur inside your consciousness. And forget about computer analogies as they are only false analogies. No bunch of electrical charges or frequencies inside a computer converted into pixel symbols on screen represent anything without us consciously reading meanings into those symbols by awareness of our human lingual and/or engineering conventions.

Emergentism can't explain how matter can give rise to something which is ontologically categorically different from matter, or the peculiar feature of the alleged emergent property to subsume everything even its own origin, matter, inside its mysterious subsumptive power.

Epiphenomenalism while not strictly a physicalist position posits consciousness as an idle by-product of the brain machinery but can't explain why should there be such a by-product in the first place, let alone able to produce such peculiar features as unity, subsumptive power, meaning, intentionality, etc.

Idealism, therefore, emerges as the only alternative, after all forms of the diehard physicalism defeated. Now Idealism can actually explain matter, whatever its exact scientific definition, by postulating that all matter are only various determinations of consciousness. The only problem however is that it implies some sort of a subjectivist non-realist demonology, as if our minds (us ourselves actually!) are some self-deceiving supernatural entities that can create and project the phenomenal world before our eyes without it (us!) normally making notice of our entire self-made show!

But a particular form of panpsychism can help us avoid this "crazy" (maybe even logically absurd) scenario, by postulating a universal/cosmic consciousness inside which all determinations understood as "matter" take place giving us the very real physical world, with human mind being some sort of a highly restricted and degraded offshoot of that supreme consciousness that perceives those determinations by partially participating in that higher consciousness.

I have find this hypothesis the only remaining view that is logically consistent, which is really so much because the foremost issue in mind-body relation debates are still the issue of logical consistency. Note that on this account, no datum of experience is ignored or dismissed or reduced, including the reality of the physical world!

With so much resolved, what I still found to be specially reassuring was that this only plausible view has been also empirically corroborated by that single revolutionary work that I have cited in my earlier answers two times already Irreducible Mind by Edward F. Kelly et al. The authors have complied several category of empirical evidence from parapsychology that support the above picture, one that had been already proposed by F. W. H. Myers, a colleague of William James, more than a century ago but simply ignored and forgotten due to the rise of crude behaviorism and its blinding lure!

  • so what is the world and body in idealism? mind, but how does a mind construct (or even give the impression of, without a substrate?) matter? sorry for my ignorance, but i can't get my head around the idea of minds having a mental substrate
    – user67675
    Commented Sep 29, 2023 at 11:52
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    @prof_post, Body and the world are determinations of some really powerful mind on this account. This supposes that consciousness is most fundamental and inherently creative. Just imagine how you can just conjure up a phoenix in your mind. That's pretty much how the world and body came to be out there by a superior consciousness. Yes, that looks like some sort of theology but that's the only consistent scenario.
    – infatuated
    Commented Sep 29, 2023 at 12:08
  • so it can cover it, but not with as much explanatory ease. though i suppose vice versa is tricky too
    – user67675
    Commented Sep 29, 2023 at 13:01
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    @prof_post Key point is that the above proposal is logically consistent, whereas physicalism is not. Furthermore, Irreducible Mind cites evidence for higher states of consciousness ("mystical") inspiring creative works of art, which really corroborates the point about a universal consciousness having created the natural world as products of its inherent creativity.
    – infatuated
    Commented Sep 29, 2023 at 13:18
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    ok thanks for reply
    – user67675
    Commented Sep 29, 2023 at 14:22
  1. Physics is experience, arranged in economical order

  2. Science always has its origin in the adaptation of thought to some definite field of experience

  3. Bodies do not produce sensations, but complexes of elements ie. complexes of sensations make up bodies

  4. Atoms are not real, only sensations are real
    Note in the nineteenth century the modern atomic theory was cutting edge and speculative

That's Ernst Mach, one of the foremost physicists of the 19th century and an inspiration to Einstein.

So yes idealism cannot 'cover' material-ism
But it 'covers' matter well enough


  1. Your verb 'cover' is not a usage I'm familiar with. I've used it as 'explain'
  2. Not too many people would call Mach an idealist. He's better known for a phenomenological stand for physics. But for the purposes of this question that comes to the same
  3. Explanation is not the same as effectiveness or prediction capability. We can assume that even staunch idealists consult doctors trained in the conventional — ie. materialistic — tradition!
  • The studies of how our minds work have revealed that we do lots of thinking unconsciously. System 1 is unconscious, and does its thinking prior to creating "experience". System 1 communicates a digest of our sensing to system 2, and that communication is through qualia. Mach's claim that experience is a prerequisite for thought, is not true of our own unconscious minds. The best of the "delusionist" books is "Incognito". It is worth a read.
    – Dcleve
    Commented Feb 27 at 6:00
  • @Dcleve Well Mach was living in the 19th century. You need to allow that as slack!
    – Rushi
    Commented Feb 27 at 6:42

Materialism was refuted by physics, specifically Einstein, when matter was shown just to be a state of energy.

The effort to salvage materialism by assuming "physicalism" is itself refuted by the nature of physics as a field of study, rather than an ontology. The explicit statement of one aspect of this problem is called Hempel's dilemma. Another is that neither physics nor science are stand-alone fields -- they are incapable of establishing a standard of epistemic knowledge, and are entirely dependent on philosophy to do so.

Pragmatically, most physicalists assume that both information and logic exist, and neither are material. One cannot DO physics with only matter, or energy. One needs both information about the matter/energy, AND a valid reasoning methodology. Both of these fall into the category of "abstract objects", or Popper's World 3, so this is effectively a dualist worldview, although it is a matter/abstraction dualism, not a matter/consciousness dualism.

Generating abstractions or consciousness from matter or energy (or from functions/algorithms, as per above, physics assumes their existence too) -- has proven to be a hard nut. A variety of solutions have been proposed for the "hard problem of consciousness" or the "hard problem of abstractions" from a physicalist POV, but so far, they fail test cases, and/or thought problems. In principle, both are at least possibly solveable, but pragmatically that has not been achieved.

Idealism is less clear than physicalism, as some idealisms are of abstractions, others are of awareness, and the two are very different. Idealisms face the same problem of physicalism, they require the spawning or explanation of very different states from a base state. Matter, and physics, would need to be generated in some way either by abstractions, or by minds, and as matter and physics are very different from either abstract concepts or the experiencing of minds, there is an analogous "hard problem of matter" for idealism. This generation is possible in principle, just as is the materialist hypothesis of minds and abstractions being generated by matter, but likewise faces challenges as to whether any proposal made by idealists is actually valid pragmatically or not. In particular, the commonality of matter between different minds is very difficult to explain.

The most productive route for any monist ontologic theory is to invoke strong emergence, where emergence laws or relationships from the substrate create the emergent structure of some other radically different thing than the substrate. This brings its own problems, as emergence is a very poorly understood concept and theory, and there ARE no general rules and principals as to when emergence happens, nor what new thing might emerge.

The other alternative is to just treat minds, physics, and abstractions as their own separate ontologies. This is what spiritual dualism does for minds, and abstract realism does for abstractions. Treating all three as separate ontologically is called Triplism, and Frege, Popper, and Penrose are the most notable advocates of ontological triplism. Both dualism and triplism require interaction principles between these ontologically distinct substrates, which is its own complexity, similar in magnitude but (to my mind) less complex than developing a set of emergence laws.

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    I think of energy as physical. It certainly isn't an idea.
    – Scott Rowe
    Commented Jul 22, 2023 at 18:36
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    Pre-GR, energy was seen as a property of matter, and as such part of materialism. Physics was just a science that studied matter. Post GR, matter is a property of energy, but what energy IS -- is vague. And physics is a field of science, without any specific ontology. But yes, energy would be part of what physics studies.
    – Dcleve
    Commented Jul 22, 2023 at 18:41
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    Mass isn't a state of energy and matter isn't mass. Mass is (representable as) a bivariable function of energy and momentum, m^2=E^2/c^4-p^2/c^2. Matter is (representable as) particles with mass. However, particles with (and without) mass have characteristics that are not reducible to mass-energy-momentum, e.g. electric charge.
    – g s
    Commented Jul 23, 2023 at 12:07
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    @gs -- WHAT mass or matter is -- is no longer clear in physics. Essentialism, defining what the base elements of the universe are, is no longer really being practices in physics. As you illustrated in your effort to characterize mass, physics has resorted instead just to math equations -- and this is exemplified by the exhortation response to "what does it mean?": "shut up and calculate". The primary essentialist inclinations among physicists today tend toward MATH reductionism, that physics (and therefore matter) is "essentially" just math. Which is -- interestingly, actually IDEALISM!!!
    – Dcleve
    Commented Sep 29, 2023 at 16:38
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    @rishi -- Expanded a bit.
    – Dcleve
    Commented Feb 26 at 14:25

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