Pan-idealism is a metaphysical system that will, in my view, solve the mind-body problem. I have been refining it over a number of years. It combines panpsychism with idealism, to reinforce the strengths (and eliminate the weaknesses) of both: First, it inherits the advantage of realism from panpsychism. Indeed, this realism is expressed with more clarity than in physicalism. Second, it inherits the advantage of monism from idealism. (Physicalism is claimed to be monist, but when physicalists attempt to solve the mind-body problem, this monism becomes diluted – unless they deny the existence of mind.)

Click on Why Panpsychists Should Also be Idealists to see a YouTube video (in which I feature) advocating this general position.

In my first book, I called the position idealist panpsychism. This is somewhat misleading. “Idealism” refers to a full-blown metaphysical category; whereas “panpsychism” refers to a comparatively minor feature: the extent of the distribution of mentality throughout the cosmos.

In my new book, Mind, Quantum, and Free Will, I link pan-idealism very closely to the physics of our universe.

Below is an outline of my ideas, as far as they had developed in a 2014 paper. Its title is overly provocative; a better one would be The Physical as entirely Secondary.

Eliminating the Physical

Eliminating the physical world is a radical attempt to solve the mind-body problem: clearly if there is no physical world as such (one that can exist, of itself, independently of mind), then the problem vanishes.  Scientists and laypeople are likely to baulk at this suggestion, until they are reassured that this metaphysical position, which I will call Copernican idealism, is consistent with science and does not deny the reality of such things as tables, dinosaurs and quarks.  Rather than attempting to prove this system true, in the manner of analytical philosophy, I will present it as a metaphysical system – a rival to physicalism – and hope that it will be seen, at least by some, as a more plausible and comprehensive account of the facts of our world.

The mind-body problem

The physical sciences offer an account of certain facts of the universe.  The mind-body problem can be summarised as asking how qualia (Chalmers 1996: 3-11), experiential qualities such as the blueness of blue and the feeling of a pain, and mental causation (Kim 1996: 125-154), for example my feeling of thirst leading me to reach for a glass of water, can be integrated in a harmonious and lucid manner so as to give an ontology that includes both scientific and experiential data.

This problem has been under intense scrutiny especially over the past two decades without anything approaching a consensus developing.  So much so that ‘mysterianism’ – McGinn’s position that humans do not possess the conceptual apparatus to tackle this problem – is still regarded by some as tenable (1999: 205).  It is my contention that the lack of success is due to the fact that nearly all workers in this field do so under the assumption of physicalism – the metaphysical position[1] that the ontological foundation of the universe is its physics and that everything mental, including qualia and mental causation, is to be understood in these terms.  In contrast I will argue here for a position in which the entirety of the physical is ontologically grounded in and subsumed by the mental.

The power and limitations of science

Science abstracts structural facts from our inter-subjective experiences of the world.  It develops laws that, with an extraordinary degree of accuracy, relate these structural facts to one another mathematically.  For ease of exposition I will suppose that there is a completed physics for our universe – one in which all experiments have the predicted outcome, at least to within the statistical limits (if any) of the perfected laws.

I take it that scientists – and not philosophers – are the best persons to determine the actual furniture F of the universe.  They might decide that, for example, this particular molecule and that particular cat are in F.  Let us call the members of F true individuals.  Catalogue F would be expected to contain, among other things, all elementary particles, fields, atoms, molecules, cells, organs, organisms.  It would probably not contain such things as rocks and galaxies, which can be taken to be merely aggregates of true individuals.

In the above, I am making a plausible bet as to the way science will ultimately go:  A hydrogen atom cannot be reduced to a proton and an electron – so long as it exists it has an irreducible unity.  Similarly, a cat it is not just a complex assemblage of elementary particles that is ‘merely a cat as it were,’ but is true individual: an irreducible hierarchy of organism, organs, cells, down to elementary particles.[2]

But science has absolute limitations that philosophers need to elucidate:  Scientists have no epistemic access to the world except through their experiences.[3]  The ‘laws’ of (even completed) physics can never amount to causal explanations – they are merely mathematical descriptions of regularities in the structural relations among the various items of furniture of the world.  Science can tell us nothing about the intrinsic nature of any item of this furniture.[4]

Copernican idealism

We will suppose that idealism is true in the following sense:

    • Every true individual in the universe is in its intrinsic nature a centre of experience (an experient)

    • Every experient has a qualitative percept of at least some other experients

    • They behave lawfully, with a degree of freedom, according to their percepts

For example, a photon is a centre of experience.  If it is a participant in a Young’s Slits experiment, it has an intrinsically qualitative percept of the apparatus, and has a certain limited, lawful agency enabling it to land where it will on the photographic screen.  On the other hand, we are certainly not assuming that electrons and other primitive individuals can think.  Note that lawful agency is described entirely idealistically – in terms of experients, percepts and volitions.  Experients can exist in hierarchies: an organic individual is one that sits above others in a hierarchy.  Organic individuals include the cat and its component parts as described above.  But ultimates (such as electrons) are not organic individuals, and neither are aggregates.  There are combination laws that relate the percepts and volitions of each organic individual to those of the individuals in the level below it.

This form of idealism leaves it up to scientists to determine what things exist and how they are arranged into hierarchies.  It merely makes a proposal about the intrinsic nature of objects in the universe.  For this reason it does not call into question the reality of anything that scientists take to exist.  (This position could be regarded as a form of panpsychism (Ells 2011: 79-80), but I now prefer to regard it first-and-foremost as an idealism because the latter, being a fundamental ontological claim, goes deeper than panpsychism, which merely makes a claim about the ubiquitous distribution of mental properties in the universe.)  Others who have held a similar position include AS Eddington in The Nature of the Physical World, William James in his later years in A Pluralistic Universe and James Ward in his 1896 and 1907 Gifford Lectures.

The next task is to illustrate how the physical as such can be eliminated in principle by reducing physical substances, properties and causes to mental substances, properties and causes:

Reducing physical substance to mental substance

We want to show that physical substance is nothing over-and-above mental substance.  But by hypothesis, under Copernican idealism, every experient has a qualitative percept of at least some other experients.  This is an axiomatic, fundamental ability that all experients have.  In particular, experients do not have to be cloaked in any mysterious additional ‘physical stuff’ in order to be perceived by other experients.  We may turn around an argument by Dennett (1991: 346) and call this mysterious physical stuff ‘phygment’ in analogy with the pigment in paint: there is no need to coat experients in mythical phygment.  (If we wish to take a more ‘process’ view of Copernican idealism, then we can maintain that each individual is a succession of short-lived experients, and apply essentially the same argument.)  Physical substance is identically mental substance.  It is perfectly respectable to talk about it, but only if we realise we are talking about mental substance (i.e. experients) under a different name.  If our use of language leads us to believe that physical substance is distinct from or over-and-above mental substance (for example, if we speak of ‘the physical as such’), then we are deluded and, to avoid this risk, it would be better to drop all reference to physical substance.

Reducing physical properties to mental properties

We want to show that physical properties are nothing over-and-above mental properties.  Length will be used as an example.  Two scientists are measuring the length of a bone.  They place a ruler beside the bone so that each end of the ruler coincides with the adjacent end of the bone.  (For simplicity I’m assuming that the bone and ruler happen to be equal in length.)  Only if Albert’s percepts are compatible with Betty’s do they know that their measurement is veridical.  We will call this empirical condition inter-subjective consilience.

One might propose that length is identically such empirical inter-subjective consilience but, as it stands, this suggestion would be hopelessly anthropocentric.  However, we can correct this by extending the condition to all experients.  We arrive at a Copernican empiricism.[5]  Take, for example, a dog.  Its perceptual apparatus has similarities to that of humans: the images of the bone and the ruler take up equal portions of the dog’s visual percept.  Its experiences as it wanders around these items are empirically consilient with the finding of Albert and Betty that the ruler and bone are equal in length.  The dog’s percept is an effective measurement of the length of the bone, even though it cannot think, and even in the absence of any humans.  Although we do not have epistemic access to the dog’s percepts, we may be very confident that they do in fact occur as described – they are part of the ontology of our idealist universe.  We can extend this to even humbler experients. For example, lay the ruler and bone end-to-end and a neutrino will have relevantly similar (but unknown) experiences in passing through each in turn.

Sketchy definition: the length of an object is obtained by maximally combining (and reconciling as outlined above) structural information from the percepts of all of the experients that perceive it – including the experients that make up the object.

This definition will not enable us to determine a particular length in practice, as no experient will have information about the percepts of all others.  It is sufficient for our purpose that, as a metaphysical and mathematical fact, such a length exists.  (If we have a natural unit, such as the Planck length, then length is simply a number.).  For example, the Moon is an aggregate.  The particles that constitute it are always experiencing and being experienced by one another.  The Moon therefore existed in a clearly-defined manner – with a precise diameter – even in the early universe before the advent of life.

Length is thus identical to reconciled information derived entirely from the domain of mind – it is consistent with an idealist metaphysic.  There is no need to suppose that there is any such thing as an additional and obscure ‘real physical length.’  Once length has been so reduced to mind, it is easy to convince oneself that the concept of space has ipso facto been reduced.

Reducing physical causation to mental causation

We want to show that physical causation is nothing over-and-above mental causation.  The model for the dynamic of the universe is given by human agency.  I am in a certain mental state in which I perceive that my hands are by my sides.  I have a volition to salute, and I then perceive that I am saluting.  My neighbours can see me perform this action.  The dynamic is entirely mentalistic in character.  Similarly ultimates, such as photons, have a certain degree of agency, with lawful freedom to act according to their percepts.  Any two photons having identical percepts will have identical predispositions to act in each possible manner – if the probability to land at A rather than B is 3/4 for one of them, then it will be 3/4 for the other.  This mentalistic lawful agency is the ontological grounding of all causation in our universe, and it underlies the laws of physics, (and also so-called ‘physical causation’), which are nothing more than the observed mathematical regularities of nature.  Because Copernican idealism has specific combination laws, it follows that two humans who are absolutely identical as hierarchies of experients (this implies they have identical bodily, brain, and mental states), and who are in identical environments, must have identical propensities to choose A rather than B.  So, in principle, the universe is not chaotic at the biological level.

The advantages of Copernican idealism

Copernican idealism is very much a framework, rather than a single theory.  One still needs to specify the percepts and laws of volition for ultimates, and also laws of combination.  It gives clear answers to many problems in the philosophy of mind, and also to those associated with most other variants of idealism:

    • The explanatory gap: how can mind and matter be identical when they have such different properties?  Everything physical (substances, properties and causation) can be reduced to mental dittos.  There is no explanatory gap because we do not know anything about the physical – except through our experiences.

    • Mental causation:  This has been discussed above.  In Copernican idealism – far from making the unwarranted metaphysical assumption that ‘the physical world is causally closed’ – there is no physical causation at all, and the only dynamic is volition based upon perception.  In contrast, Kim has argued forcefully and at length that the problem of mental causation is a “profound dilemma” (1996: 236) under the assumption of physicalism (9-13).

    • Perception:  This is exemplified by Hodgson, “Light reflected from my red pen is focussed by the lenses of my eyes on to the retinas: and this results in electrical-chemical signals going to my brain, and then in further electrical-chemical processes within my brain: and I see the red pen” (emphasis original 1991: 1).  In contrast to physicalism, in Copernican idealism this process does not involve a mysterious change of ontological category at the last step; instead, each event in this sequence is an act of perception and volition.

    • The problem of qualia:  In Copernican idealism there can be no problem of qualia because they are fundamental, and it is the presence of qualia that distinguishes concrete reality from an abstract mathematical model.  Instead there is the problem of accounting for the physical in terms of qualitative percepts.  This has been the burden of this paper, but two points might usefully be made.  Structures are abstracted from percepts analogously to the way a vaguely oblong region may sometimes be seen in the qualitative field that is a Mark Rothko painting.  Abstraction (literally ‘taking away’) is not an obscure notion.

    • The problem of zombies: According to Chalmers, philosophical zombies are putative creatures, physically and behaviourally identical to us, but lacking any mind (1996: 94).  Two questions are, ‘Are zombies conceivable?  Why are we not zombies?’  In Copernican idealism, to exist concretely as an individual is exactly to be an experient.  My brain (physics and all) is nothing over-and-above a hierarchy of experients.  So, take away my mind (in particular, that part associated with thinking), and you have, in that very action, annihilated a chunk of my brain.

    • Realism about objects in the world:  This is a problem with many forms of idealism, but is here accepted by hypothesis.  For the most part, we leave it to scientists to determine what is real, but it is for philosophers to establish the character of these objects.[6]

    • Consistency with science:  Definitions of physical properties are made by applying the Copernican principle to the empirical methods that scientists actually use.  If a bone has a certain length as determined by Copernican idealism, then a fortiori, it must have the same length according to scientists (who are a subset of all experients).


There are difficulties with the proposal made here, which will be discussed briefly:

    • How are explicit connections to be made between experiences and the findings of science?  In particular, how are specific laws of intersubjective consilience to be discovered?

    • How and under what circumstances do primitive experients combine into hierarchies of more complex experients?  (This is known by panpsychists as the ‘combination problem’.)

The cosmos is naturally stratified into layers described by the sciences, so even an advanced alien intelligence will have distinct sciences of physics, chemistry, and biology.  Moreover it will have the concepts of physical ultimate, atom, molecule, cell, and so on.  The combination problem will be solved, I believe, by having ‘vertical’ combination laws that tell under what circumstances and with what probability experients at one level will combine into a single experient at the next level above (and similarly for dissolution of a high-level experient into several that belong to the level below).  Combination laws do not require any explanation because they are fundamental, being no more than descriptions of the way our universe happens to be.  In a similar way, it is not required to explain why the laws of physics are the way they are.

Because human beings have evolved in a continuous manner from the simplest of experients in the far distant past, I believe it is more plausible than not that the combination laws are recursive, relating each level to the next and more complex level.  If this were not so, evolution would have to proceed by a succession of little mysteries, to enable us to have evolved from a collection of atoms to the complex systems that we are.

According to Copernican idealism, the physical facts at any level are a reflection of structural information abstracted from the percepts of experients at that level and so, rightly understood, science already gives us some limited insight into mind.  I also believe that it is reasonable to adopt a principle of translucency, whereby any experient’s percepts must, on at least some occasions, be manifest in its volitions, and hence in its physical state as observed by others.  From this principle we may be confident that an electron, for example, cannot silently ponder philosophical issues.  More importantly, the physical properties and behaviour of an electron will give us some insight into its primitive percepts and volitions.

It is undeniable that these difficulties are extremely tough, and any solution to them must lie in the far future.  Nonetheless, there is nothing here that is as impossible as the mind-body problem that besets philosophers who presume physicalism, and which has been named by Chalmers the “Hard Problem” (1996: xii-xiii).

Giving up on the physical

Copernican idealism can be summarised in terms of ‘persons’.  (1) Every individual thing that exists in the universe is an experient: a (probably very simple) subject with a first-person ontology.  (2) Certain experients have consilient experiences and the inference from this consilience is that something else exists.  This other thing is another subject (or perhaps an aggregate or a hierarchical system of subjects).  What is observed belongs to the same ontological category as the observers.  We may loosely say that the universe has a second-person (intersubjective) epistemology, even in the more common situations in which the observing subjects have neither cognitive powers, nor any means to communicate and share their percepts.  In most cases consilience exists solely as a mathematical fact about a set of percepts.  (3) There is no ‘third person’ in the ontology of Copernican idealism.

What are we giving up if we stop giving credence to the notion of ‘the physical as such’?  In a word: nothing.  For example, the belief that there is a ‘real physical distance as such’ between objects A and B, which has some meaning absent experience, is unintelligible.  According to Copernican idealism, everything claimed by scientists to exist indeed does so, provided only that they are correct in their expert assessments, in a manner essentially the same (but perhaps much simplified) as our own mode of existence as persons.  That is to say, in a way consistent with such concrete and familiar actualities as volition, pain and the aroma of coffee.

Recommended reading

Chalmers, David The Character of Consciousness OUP, Oxford 2010 is a thorough survey of the current state of play in the philosophy of mind.  Possible metaphysical positions are classified into types (111-137), including one close to that which is outlined here (133).

Berkeley, George Principles of Human Knowledge and Three Dialogues OUP, Oxford 1996 thoroughly demolishes the coherence of the notion of ‘matter’.  This attack is logically distinct from his defence of his implausibly sparse idealism.


Chalmers, David (1996)  The Conscious Mind.  OUP, Oxford

Dennett, Daniel (1991)  Consciousness Explained.  Little Brown, Boston

Ells, Peter (2011)  Panpsychism.  John Hunt Publishing, Winchester

Hodgson, David (1991)  The Mind Matters.   OUP, Oxford

Kim, Jaegwon (1996)  Philosophy of Mind.  Westview, Oxford

Leibniz, G (1714)  Monadology.  English translation (retrieved 5 May 2014) at

McGinn, Colin (1999)  The Mysterious Flame.   Basic Books, Oxford

[1]      As will become clear, physicalism is indeed one among several contending metaphysical positions.  Contrary to what many believe, it is not necessitated by our scientific understanding.

[2]      This is a change from my earlier position, which was fully reductionist (Ells 2011: 37).

[3]      Scientists also have theoretical access to the world, but this is by way of mental models that are themselves ultimately grounded in experience.

[4]      At least some items in the world, namely ourselves, have an intrinsic nature, but science (absent metaphysical assumptions) cannot observe it.  This is essentially the argument made by Leibniz in his discussion of the Mill (1714:  ¶17).

[5]      ‘Copernican’ by analogy with the way this astronomer removed humans from a special, central place in the cosmos.

[6]      Some philosophers claim that an entity is ‘real’ only if it is possible for it to exist unperceived.  All idealists reject this conception because, among its many other problems, it begs the question of physicalism.

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