Part Two: Philosophical Considerations

5. Ontology

What sort of world do you live in? Are there ‘nothing but’ atoms and the void? Do or could immaterial or even disembodied minds exist? Is, by contrast, the world you inhabit one big mind, and our lives figments in a cosmic dream?

Ontology

These sorts of questions are ontological. Ontology is the study of being or existence, dealing with what really exists in contrast with what only seems to exist, and with what permanently exists in contrast with what has a temporary existence.[1] It also deals with that which exists independently and unconditionally in contrast with what which exists dependently and conditionally.

In a sense, an ontology is a theory of everything. A materialist ontology, for example, tries to reduce everything to ‘matter’ or its derivatives. By contrast, an idealist (mind-only) ontology does the opposite and reduces everything to mind. But these possibilities form only two limited kinds of ontology. Frege and Penrose, for example, split the universe into three ‘worlds’; the mental, the physical and the mathematical, and Karl Popper did something similar.[2]

In ontology, one does not even have to restrict oneself to the visible, accessible world. One can posit any number of unseen, hidden or inaccessible alternate ‘worlds’ about us. These might be theological or pre-scientific in nature (a posited ‘heaven’ or ‘hell’) or otherwise supernatural. These worlds might be inhabited by unseen entities, like angels, demons or spirits. Other sorts of alternate worlds are supposed in philosophy and science. The philosopher David Lewis speculated about an infinite plurality of unseen, inaccessible worlds where the rules were different from our own, and the ‘many worlds’ interpretation of quantum theory invokes unseen worlds splitting every time a certain kind of measurement is made.[3]

The crucial point, for our purposes, is that ontology is a metaphysical and theoretical exercise rather than a primarily empirical one. Metaphysics is the theoretical philosophy of being and knowing, and is often employed, overtly or covertly, in the philosophy of mind and neuroscience. Midgley has gone as far as to claim that most arguments in the Journal of Consciousness Studies arise because of metaphysical differences.[4] This is because ontology is about more than the existence or otherwise of unseen worlds; it also deals with potential divisions or unities in the world in which we live.

The World

On the face of it, we live in one, inclusive world.[5] The philosopher David Lewis, who argued for a plurality of isolated and causally diverse ‘other’ worlds, put it this way:

The world we live in is a very inclusive thing. Every stick and stone you have ever seen is part of it. And so are you or I. And so are the planet Earth, the solar system, the entire Milky Way, the remote galaxies we see through telescopes … There is nothing so far away from us as not to be part of our world … Likewise the world is inclusive in time. No long-gone ancient Romans, no long-gone pterodactyls … are too far in the past … [not] to be part of this same world. Maybe, as I myself think, the world is a big physical object; or maybe some parts of it are entelechies or spirits or auras or deities or other things unknown to physics.[6]

The majority of scientists probably concur with Lewis, and agree that the world in which we inhabit is a unified, physical entity. Walter and Heckman comment that physicalism has ‘outrun its dualistic (and idealistic) competitors and has reached nearly unanimous consensus’. They comment that ‘The world we live in, it is quite reasonable to believe, is a physical world, not only at its most fundamental level, but through and through …’[7] This might, to someone raised in Western society, seem thoroughly reasonable, but it remains a metaphysical statement rather than an empirical or factual one.

One reason is that it is very difficult or even impossible to define ‘physical’ in a comprehensive or definitive way, and there remain philosophers who claim that there is no evidence for physicalism.[8] The second is that the definitions of ‘physical’ or ‘material’ have radically changed from their initial definition in early modern times. What twenty-first century physicists mean by ‘physical’ is very different from what Descartes or Newton meant.

Truth by Declaration

The claim that physicalism must or is likely to be the ‘correct’ ontology for the world that we live in is very common, and is often justified on empirical grounds. For example, Searle claims that we know too much for, say, an idealist, or mind-only, view to be correct. ‘It is hard to send men to the Moon and bring them back and then take seriously the problem, for example, of whether the external world really exists.’[9] Searle’s claim is that modern empirical science has advanced in such directions, achieved so much in terms of the manipulation of the physical world, that this is enough to exclude an idealistic alternative. In other words, he is attempting to resolve a metaphysical dispute by using observational data.

But even in experimental science, empirical attempts to resolve differences in theoretical perspectives often have significant limits.[10] It is even less likely that such an esoteric exercise as deciding a ‘correct’ ontology can be resolved in this way. An idealist might argue, for example, that the reason why we have so much knowledge about apparently physical things is because our minds ‘fill in the gaps’ as we go along, and the mind-world subtly moulds itself to our general expectations. In this interpretation, we got to the Moon because a collective belief and a mass movement of thought caused us to create the machines we thought we needed to get there (even a physicalist might accept this as metaphorically true).

So a committed idealist would probably be able to come up with arguments that were plausible to them and logically consistent within their framework of thought.

We should also note that Searle is already committed to his perspective, and the numerous facts of science and technology just reinforce a view already firmly held. Searle also ignores the idealistic bent of a number of theoretical physicists, some of whom speculate about participatory universes and that consciousness might underlie everything.[11] Whether or not these speculations are valid,[12] they seem a long way from the sort of objectivism—derived from classical physics—that underlies most of current work in the philosophy of mind.[13]

The primary problem with ontological debates is that many of the combatants of different stripes decide on an ‘ism’ to follow a priori and end up defending it to the hilt whilst ignoring often valid arguments from their opponents. Bolender observed that ‘Nature’s imagination is richer than the imaginations of the older, less informed philosophers who invented the isms which we are now … so slavishly following’.[14] He quotes Freeman Dyson, who suggests that it is more desirable to makes use of one’s unfettered imagination than follow an ism. Dyson went on to say that allying oneself with a school of thought as the basis of one’s theory construction is a sure way to fall from brilliance to sterility. We need to heed this caution.

A Variety of Ontologies

I shall now make a brief survey of some ontological alternatives, including variants of physicalism. An initial point is that it is possible to construct many different ontologies and, if we include non-Western ones, that there may be thousands or more in current existence. If we truly and deeply appreciate the sheer variety of ontologies, then it begins to seem a little conceited—not to mention unlikely—to assume that there must be just one ‘correct’ one. It is rather more likely that different ones might be useful in different social, scientific, and existential contexts. For brevity, I will focus upon Western, post-Cartesian ontologies.

Monistic Ontologies

These ontologies typically assume that everything can be reduced to one ‘stuff’, essence, or principle. As we saw in the introduction, monism can also be defined as ‘[t]he metaphysical position that all is the manifestation of a single underlying reality, principle, essence, or substance, and is governed by a universal set of laws …’[15] Rucker [16] points out that there has long been a very strong urge to reduce the world’s diverse phenomena to one kind of essence or stuff, and that the candidates have included mind, matter, sensation, and form.

Ontology	Substance(s)	Closure principle?	Features
Monistic Materialism	Matter	Conserved	Everything reduces to ‘matter’ (see also Popper’s subclassifications, Table 2)
Monistic Idealism	Mind	Conserved	Everything reduces to ‘mind’
‘Simulation’ Models	No substance specification required	Depends on ontology of the simulator’s universe	We are living in a post-human simulation of the past
Neutral Monism	Neutral single substance	Conserved	Mind and matter are derived from a single, ultimate substance
Cartesian Dualism	Mind, Matter	Violated	Mind and matter are distinct but interacting substances
Bergson’s ‘Filter’ Dualism	Mind, Matter	Violated	The brain acts as a filter through which a ‘Mind-at-Large’ flows
Jamesian ‘Permission’ Dualism	No substance specification required	Violated	The brain releases or permits mental events
Popperian Property Dualism	No substance specification required	Violated?	Mind is a distinct, emergent property of the human organism
Koestler’s Dualism	No substance specification required	Violated?	Mind is a distinct, emergent property/quality of the human organism. Multiple sorts of emergent properties possible
Stapp’s Dual-Process Theory	No substance specification required	Violated	Consciousness can be seen as a distinct nondeterministic system that ‘interrogates’ deterministic brain systems

Table 1. Some Western Post-Cartesian Mind-Matter Ontologies.

This move is termed a monism of kinds, and was initially mystically motivated. This drive to so reduce reality is very strong in the West, and represents a persistent theme in science.[17] For example, seventeenth-century chemistry was dominated by the search for a universal principle known as ‘quintessence’, a kind of universal agent or solvent responsible for all chemical reactions.[18] More recently, we have seen a search for a ‘theory of everything’, or Unified Field Theory, which seeks theoretically to unify all the major forces in the universe. Wertheim suggests that the drive to do this is inherited from the theological principle of relating all of creation back to a single God. Monistic, Western ontologies often try to reduce the world that we experience either to ‘mind’ or to ‘matter’. We shall consider the idealist, or mind-only, option first.

Monistic Idealism

The proposal that the universe in which we live is nothing but mind was most famously voiced by Bishop Berkeley (1685–1753). Berkeley’s version contends that we can only know the ideas and sensations of objects, and not abstractions like ‘matter’.[19] Berkeley thought it impossible to talk about an object’s being, and that we should instead only talk of an object’s being perceived by someone.[20]

He went further, however, because he supposed that nothing that appears to be ‘out there’ in the world has any inherent existence at all. This creates a problem of stability, which is well illustrated by a short story of Borges about a land with an idealist philosophy. In this land, books are supposed to be the product of one anonymous author; lost objects are refabricated, and it is supposed that forgotten items eventually disappear. There are no nouns because nothing is supposed to exist; instead, verbs describe objects. The world is supposed to be unstable in the manner of the mind.[21] Berkeley’s solution to this sort of objection is to suppose that objects that are currently not being perceived by humans were kept going by the omniscient mind of God.

Marshall advocates a form of Berkeleyan metaphysics ‘suitably modified in the light of mystical experience and modern science’.[22] His study of extroversive mystical experiences, such as those described in our introduction (statements 3 & 5), suggests to him that the universe we see, including physical objects like trees, stones and galaxies, should be considered ‘mental’ in nature. Like Berkeley’s, Marshall’s proposition requires a ‘great mind’ to work.

More recent, rationalist-physicalist versions of this sort of theory have eschewed God’s all-seeing eye in favour of post-humans in the remote future setting up a computer simulation of the past. Nick Bostrom argues that there is a significant chance that we are living in such a simulation.[23] This theory, however, is not idealistic in the Berkeleyan sense because the ultimate, non-simulated reality of the post-humans is also presumably materialistic.

Idealistic philosophies have been more influential than might at first sight be supposed. An anti-real or instrumentalist approach to the theories of science owes much to Berkeleyan idealism (see chapter six). Recent and problematic interpretations of quantum theory are also idealistic in spirit, although the issue of the mind of God is generally ignored.[24] The problem with idealism is that it often has low pragmatics in many practical contexts, as illustrated by Berkeley’s rejection of a physical theory of sound.[25] In extremis, if everything is one big thought, then one does not have to find workable physical-type explanations for anything.

Monistic Physicalism

As noted, this is considered by many to be the only viable contender. ‘Matter’ or ‘physical’ processes are primary, and so mind and consciousness must be secondary derivations. This becomes explicit when we consider evolutionary theory. According to the dominant, cosmological and Darwinian accounts, the universe began with only simple matter and energy, which gradually evolved into more complex forms (stars, galaxies, planets, then life) over time. A significant body of evidence suggests that minds are only possessed by relatively advanced animals, and consciousness by a subset of these animals. This world-picture strongly suggests that mind and consciousness are the secondary products of complex arrangements of matter. Indeed, some extreme versions suggest that minds and consciousness are (1) reducible to matter, and (2) must therefore be linguistic or neurological ‘illusions’.

Karl Popper subdivided this general, materialistic approach into four subclassifications (Table 2). It might seem odd to include panpsychism, a stance that holds that all matter has an inside or ‘interior’ quality, as a materialist theory,[26] but Popper classified a theory as materialist by whether or not it violated the closure principle. His aim was to critique all four of these positions.

Ontology	Features	Proponent(s)
Radical or eliminative materialism	Mind, consciousnesss, subjective experiences do not exist	Dennett, the Churchlands, Rorty, Ryle, J.B. Watson
Panpsychism	All matter has an ‘inside’ or mental quality	Chalmers, Spinoza, Leibniz
Epiphenomenalism	‘Inside’ qualities limited to higher animals and not causally effective	T.H. Huxley, Wegner, Carter
Identity theory	Mental events and consciousness ‘are’ brain or neural events	Damasio, Crick, Koch, Baars

Table 2. Popper’s Classification of Materialisms.

Another shared feature of these theories is ontological reductionism.[27] This is the idea that one kind of entity can be reduced to a structure of other kinds of entity. It is asserted that subjective states, selves, behaviours, consciousness can be reduced to neural structures. Bennett and Hacker define such reductionism as ‘a commitment to the complete explanation of nature and behaviour of entities of a given type in terms of the nature and behaviour of their constituents’.[28] So subjective experiences, for example, can be wholly explained in terms of patterns of ‘neural activation’.

Radical or eliminative materialism

According to this view, conscious and mental processes are non-existent or are not scientifically analysable and so in effect non-existent. This was the behaviourist position. Today’s eliminative materialists argue slightly differently. Instead of the mind being a ‘black box’, they tend to characterize it as a vast assembly of functional mechanisms, each specialized for a sub-task.[29] Eliminativists argue that once we have a specific architecture for this machine, then we will not need anything extra (qualia, consciousness, subjectivity) to account for its operations.

Paul Feyerabend is credited as one of the creators of the eliminativist position. In two articles written in 1963, he claimed that mental events were incommensurable with the physical models of science and that the successes of science indicated that one should be able to construct a worldview where the mind/body question was irrelevant, in the same way that many of the dilemmas created by Aristotelian physics became irrelevant with the advent of Galilean physics.[30] He claimed that such a conceptual change would eliminate existing arguments against materialism and end the philosophical mind/body problem.[31] I will discuss this particular claim in chapter eleven, in the context of Feyerabend’s later ideas concerning subjectivity and epistemological pluralism.

Panpsychism

This is the belief that all matter has an ‘interior’ aspect, and is not always associated with a materialist viewpoint. The belief was current amongst the Ancient Greeks, and the Vendanta schools today hold a comparable view.[32] Early modern thinkers who advocated panpsychist views were Leibniz and Spinoza. More recently, transpersonal thinkers like Tielhard de Chardin and Ken Wilber have built entire cosmologies upon the notion that the universe has an ‘interior’ as well as an exterior aspect.[33]

Popper’s primary objection to panpsychism was that the assumption that there must be some sort of precursor of psychical processes was both trivial and vague. He claimed that ‘to insist that this [something in evolutionary history] must be mind-like and that it can be attributed to atoms is a misleading way of arguing’.[34] Panpsychism also sidesteps the very deep problem of the emergence of novelty in the universe.[35]

Popper argued that we already know examples of processes in nature that are emergent in the sense that they lead to properties that were not present before. The solidity of crystals emerges effectively from nowhere, as does the capacity for memory or, for that matter, information. In a similar manner, we should not assume that anything that could be termed ‘mental’ or ‘psychic’ is present in the precursors to organisms with minds. It is easier to accept that just as there is a step from non-life to life, there is a comparable step from non-minds to minds.

We might also claim that the attribution of a human trait to the whole universe is both anthropomorphic and unparsimonious. Those of us raised in the Western scientific tradition are accustomed to thinking of most of the universe as non-living, and panpsychism seems closer to an animistic way of thinking, where life is projected onto everything. A number of writers have, however, advanced arguments for a teleological or even living universe, arguing that it is just as anthropomorphic to project mechanism onto the universe, as many in conventional science often do.[36] But the crux in the current context is whether consciousness is such a novel problem that it requires us to posit panpsychism.

Epiphenomenalism

Epiphenomenalists assert that conscious thoughts are produced by brain function but do not have any causal effect on the brain. The original analogy, given by Thomas Huxley, was that of a steam-whistle. Just as the steam-whistle constitutes a side-effect of an engine’s operations without any causal influence, so in epiphenomenalism mental events are causally ineffective side-effects of neurophysiological mechanisms. Pains, for example, do not cause us to wince but are instead caused by the same neurophysiological events that cause the wince.[37]

Epiphenomenalism is a surprisingly popular position in the cognitive sciences, and will be discussed in greater length in later chapters. One champion of this approach is Wegner, who sees conscious will as an illusion, cognitive emotion, or after-effect of neural processes.[38] Carter, too, advances the theory that consciousness itself might be a causally ineffective property that emerges from the architecture of a whole, working brain.[39] Experimental evidence of various kinds is often invoked to justify this epiphenomenal approach. Specifically, there are experiments that record neurological activity that occurs before awareness of an event or personal volition of which we are conscious.[40] The conclusion drawn from this is that since neural firing occurs before conscious awareness, then the underlying neurological mechanisms must be efficacious and not the conscious thoughts.

These experiments will be discussed in later chapters, but it needs to be conceded that at the very least they suggest that antecedent neural activity is a necessary, if not sufficient, corollary of decision-making and volition. They also suggest that volition is not a unitary process but part of a wider causal process. However, we need to bear in mind that many of the observers are for various reasons strongly predisposed towards epiphenomenalism, and that experimental results are often ambiguous and can be interpreted in a number of different ways.

Popper saw epiphenomenalism as incompatible with Darwinism. He held that the theory of natural selection is currently the only theory that explains the emergence of novelty in the world. Secondly, natural selection is concerned with physical survival, or the selection of features that favour the survival of the organism. However, this clashes with epiphenomenalism because the theory supposes that mental events have no causal efficacy. If mental events have no causal efficacy, then they cannot contribute to the survival of the organism. Therefore, according to Popper, consciousness cannot have emerged through natural selection.

This argument seems in some ways compelling. If conscious will, for example, can be reduced to a ‘cognitive emotion’ or after-effect, then it is hard to see why it needed to evolve in the first place. If human beings can get along in survival terms as mechanisms, and this additional cognitive emotion makes no difference to that function, then it is unclear why or how that emotion could evolve in the first place.

One way of getting round this might be to classify conscious experience as a ‘spandrel’.[41] This is a term invented by the evolutionary biologists Gould and Lewontin to describe a feature that is a by-product of evolution rather than a result of adaptive selection.[42] An evolutionary spandrel is supposed to be a by-product of a structural requirement and thus could be causally inert.

Despite this, epiphenomenalism seems in many ways an unsatisfactory ontology. The main reason is that it posits a causal system that only goes one way, which, as Midgley points out, is unheard of in nature.[43] Secondly, it remains a hangover from attempts to create a universal theory of the universe in purely mechanistic terms, with consciousness tacked on as an afterthought. There are surely better ways than this.

Identity theory

Identity theory, or ‘central-state’ theory or, in some versions, nonreductive physicalism,[44] does not deny subjective states but asserts that they simply ‘are’ neural activity. For example, in interview, Pat Churchland expressed the hope that one day we will be able to say ‘Aha, this is it. This pattern of [neural] activation in this context when the brain stem is doing such and such, that just is a sensation of red’.[45] This is not the sort of statement that one can take at face value, and is an expression of ontological reductionism, or the reducing on one kind of entity to another. It is again a philosophical rather than a purely empirical wish.

Although (with epiphenomenalism) identity theory is held to be the most plausible theory, it boils down to the assertion that subjective states and neural states ‘are’ somehow the same. However plausibly formulated, this remains an expression of faith.

Identity theory runs into other problems with respect to causal redundancy.[46] In logical form, the argument goes something like this;[47] Suppose mental states must supervene or are dependent upon physical states. So every time there is a mental change, there must be a corresponding physical change to accompany it. But if this is true, and physical events are considered primary or underlying, then it implies that we can do without mental states at all. This is because if physical processes and mental processes are exclusive of one another, then in logical terms, one can be reduced to the other. And in physicalism, this means effectively discarding any notion of mental causation.

This sort of point has been made across the philosophical board. Kim and Heil have both argued that non-reductive physicalism, which is a currently popular form of identity theory, entails the causal irrelevance of the mind to both mental and physical effects.[48] So, in this theory, mental states end up as causally irrelevant as those in the epiphenomenal theory, because they are supposed to be exclusive. In these accounts, we do not need to invoke mental or subjective states to explain behaviour, hence the strong impulse to label feelings of volition as ‘illusions’. To the strict materialist, then, it seems most parsimonious to say that mental states do not exist.

These sorts of problems with identity theory should make it clearer why there is a strong tendency to downplay or excise consciousness as anything causal. The varieties of epiphenomenalism or non-reductive physicalism that might as well be epiphenomenal can be seen as a concession to the existence of subjective states whilst simultaneously denying them any causal effect on the universe.[49] So the principle of causal closure is retained but at the cost of apparently contradicting our everyday actions.

Dualist Ontologies

Dualist ontologies hold that there exist not one but two domains, essences or principles. The classic example is the substance dualism of Descartes. In most contemporary books on consciousness, this theory is usually raised to be dismissed. Blackmore states bluntly that:

The insuperable problem for substance dualism is how the mind interacts with the body when the two are made of different substances … If thoughts can affect brain cells then either they work by magic or they must be using some kind of energy or matter. In this case they are physical stuff and not purely mental.[50]

Blackmore’s sentiments are very widely held, but they are not as airtight as they might seem. Popper, whilst not advocating substance dualism, addressed this issue. He pointed out that even if we were to presuppose the idea of an ultimate explanation based on essentialist substances, then the dissimilarity of substances argument would not necessarily create an argument against their possible interaction. Current physics, which does not presuppose the existence of one or more ultimate essences, suggests that the action of bodies upon bodies is mediated by fields (gravitational, electrical). So like does not act upon like here, either.[51] So this objection to substance dualism (or vitalism for that matter)[52] is not necessarily valid.

John Beloff was a recent advocate of Cartesian dualism. The reasons he gave were his belief in free will, his belief in a continuous self or ego, and his belief in the existence of psi or psychic phenomena.[53] It must be said that none of these reasons necessarily leads to a substance dualist position, although the conception of an independent mental realm seems naturally congenial to all three ideas.

Filter and Permission Theories of Mind

These theories suppose that the brain is like a television set that filters or limits the mind, rather as a television receives a signal from elsewhere. The theories can be interpreted in terms of a separate ‘stuff’, but this is not compulsory. Henri Bergson and William James considered both filter and permission models of consciousness. Myers’ theory of the subliminal mind could also be interpreted in such terms, although he was more committed to the idea of an eternal Platonic ‘self’.

There are two major issues with filter theories. The first is whether the theory is internally coherent. The second is whether such a theory can be used to gain a more comprehensive understanding of conscious and mental processes.

Firstly, it is not clear that filter theories are very consistent in the way that, for all its faults, physicalism can be. This can be clarified with a look at the filter theory of memory. Some have speculated that brains, instead of storing memories, access them from a sort of ‘global memory bank’ outside. Both Gauld and Blackmore, writers with very different philosophical views, reject such a theory, for similar reasons.[54] In such a system, memories would have to be stored as specific traces. This would allow any brain to ‘sort’ through memories it needed at any one time. But this relies upon a naïve view of categorization or how, in a memory system, objects are classed as similar to one another or recognized as distinct. As Blackmore points out, my notion of a house might be quite different from yours. The Platonic idea that there is a simple representation of a ‘house’ floating out there seems very unlikely.

Similar sorts of problems also dog ‘holographic’ models of the mind. This sort of theory proposes that nature is structured like a hologram, and the brain as an instrument by which this holographic reality is analysed. This theory has been embraced by some as potentially explaining parapsychological phenomena like telepathy and clairvoyance. Unfortunately, it is also a somewhat incoherent theory, and Stephen Braude objects to it on several grounds.

Firstly, he objects to the reduction of the world into interference patterns. He also highlights its atomistic thrust, because such patterns are held to be the building blocks of familiar perceptual and experiential reality. The theory is, therefore, committed to the parsing of reality into elements of the frequency domain and that the ‘objects, events or states of affairs of our familiar reality are simply ordered arrangements or structures’.[55]

Braude correctly observed that no such preferred parsing exists in nature. The classification of objects in everyday life and in science can be seen as to an extent arbitrary. To illustrate this he invites us to try and count the number of ‘things’ in one’s room, which of course depends upon how one classifies a ‘thing’. Likewise, there is not a preferred parsing to a person’s subjective states; a person’s memories of a specific event, say their thirtieth birthday, may be subdivided in any number of ways.

As Braude points out, the elements of a mental state only exist relative to some context in which they will be appropriate. This issue is linked to the wider problem of what—if anything—might be meant by a thought ‘structure’, which will be examined in more detail later on. For now, it is sufficient to note that the holographic theory depends upon positing certain types of preferred but implausible sorts of structures, and in its current form at least seems deeply incoherent.

If the theoretical underpinnings of filter theory are really so shaky, what can we make of the evidence cited in support of such theories? There has been a recent, and in many ways impressive, attempt to marshal evidence that falsifies biological naturalism and points in the direction of some sort of filter or dualist theory.[56] The cited evidence is that which is typically dismissed by most cognitive scientists in part because of its perceived unlikelihood but also because of its rarity and difficulty to reproduce. It includes; psi phenomena (ESP, telepathy, clairvoyance, psychokinesis), extreme psychophysical influences (placebo effects, voodoo death, stigmata), and evidence of the survival of personality beyond bodily death (memories/birthmarks from previous lives, mediumship, Near-Death Experiences).

A full consideration of the place of ‘rogue phenomena’ in the mind-sciences must wait for a later chapter, but one observation should be made here. One can immediately see why such evidence would be dismissed by most scientists. The reason is that many of these phenomena seem characteristic of a pre-scientific or animistic world-view, and belief in such things can be seen as atavistic or even anti-Enlightenment. To admit the validity of the evidence of parapsychology, say, would be to some a step backwards. This makes an impartial consideration of ‘rogue phenomena’, especially the more extreme forms, terribly difficult in a modern setting.

Despite this, such phenomena are worthy of attention because they are hard to dismiss completely. Sagan, a career sceptic, grudgingly admitted to the persistence of three parapsychological anomalies that bore further investigation.[57] If only a small portion of these phenomena are valid, then they might have the potential to allow us to modify or expand our views of consciousness and mental causation. However, we must also remember the earlier observation that empirical data in isolation cannot allow us to definitively decide between differences in ontology. There are simply too many ambiguities and too many potential differences in interpretation, and what looks like a compelling case to one might not to another.

Trialist Worlds

We are not committed to parsing the world into just one or two bits. Karl Popper divided the world into three sub-worlds. World 1 is the physical world of processes, forces, fields and material bodies. World 2 is the world of mental states. World 3 consisted of the products of the human mind, such as stories, explanatory myths, tools and scientific theories.[58] World 3 objects, like books or sculptures, can exist simultaneously as physical and mental (World 1 and 2 objects) but Popper argued that the content, which remains invariant in copies and editions, belongs in World 3. So this book might be instantiated electronically or physically, but its content remains the same (in a sense, Popper was talking about information of a particular form).

Popper also argued that World 3 objects could be unembodied. This is an issue as old as Plato, and hinges upon whether, for example, mathematical concepts really exist before they are discovered or invented by a mathematician. Popper claimed that with the invention or discovery of natural numbers there came into existence odd and even numbers before anyone noticed the fact. This issue of independent existence, in Popper’s mind, constituted an entity’s separation into a world of its own. So in a sense the existence of odd and even numbers does not fully ‘supervene’ upon the physical world, and might indeed be thought to exist in an independent, or semi-independent, Platonic ‘world’. This conceptual world is not strictly physical, but it is not strictly mental either because it is not fully dependent upon either for an ‘existence’. Hence the need for three worlds rather than two.

Frege and Penrose also split the world into three, but more along the lines of Plato; they hold that there is a mental world, a physical world, and a mathematical world. Penrose’s arguments for an independent mathematical world are similar to Popper’s, in that he argues that if, for example, a mathematical assertion can be settled one way or another by ‘some appropriate form of mathematical reasoning’ then it cannot be considered a subjective opinion but constitutes some form of objective truth.[59] Penrose states that the mathematical assertions that belong to Plato’s world are those that are objectively true, independent of subjective opinion. He suggests that this abstract Platonic ‘world’ is also where we build our models in physics.

‘Trialism’ of either the Popper–Eccles or the Penrose–Frege sort is rejected by John Searle, who regards it as worse than dualism. He suggests that it is a kind of mystification to suppose that just because we invent scientific theories or write poems that these somehow inhabit a separate realm ‘and not part of the one real world we all live in’.[60] Searle concedes that properties, numbers and universals do exist but calls this observation ‘trivial’ as they remain human creations. He does not believe that the Penrose–Frege view can be given a coherent formulation. The Popper–Eccles version of trialism is said to fail because ‘the world of culture is a part of the one real world that we all inhabit and indeed contains applications of biological capacities for consciousness and intentionality’.[61]

Searle’s objections seem to me to miss the point somewhat. The issue is not whether culture or mathematics exist within the ‘real world that we all inhabit’, but whether it is useful to parse the world in particular ways. In a sense, ontological disputes that concern the accessible world that Lewis described so eloquently can be characterized as a dispute between splitters and lumpers, splitters being those who see it as desirable to divide the totality of reality in different ways and lumpers who prefer to see it as an undifferentiated whole. Some, all, or none of the disputants might be correct.

Penrose could be seen as a splitter; but he emphasizes that his view of Platonic existence is ‘simply a matter of objectivity’ and ‘should certainly not be viewed as “mystical” or “unscientific”’.[62] And as we have seen, those who insist that our world should only be viewed as one seamless reality are hardly immune from accusations of mysticism. And there seems little mystical about considering whether mathematical or cultural entities have some form of abstract independence. What we have here is an objection based upon the assumption that monism is the only reasonable way of looking at the world.

Mind and Matter as Metaphors

If nothing else, this brief survey has shown that there seem to be many possible ways of parsing the world in which we live, and that it is by no means obvious that there is one true ontology to which we must or should adhere. This might seem surprising in a culture where these questions are often held to have been definitively settled in favour of physicalism.

I would, in this spirit, challenge attempts to definitively split or lump the world into its ‘true’ components. To do so is to ignore the metaphorical nature of these parsings.[63] There has long been considerable doubt as to whether this is desirable or even necessary in science. For example, Bertrand Russell was unconvinced that any meaning could be attached to either a substantial ‘mind’ or ‘matter’. He noted that ‘[e]veryone knows that “mind” is what an idealist thinks there is nothing else but, and “matter” is what a materialist thinks the same about’.[64] (This objection also applies to neutral monism, which posits a singular ‘stuff’ that is neither mind nor matter.)[65]

Instead, Russell defined ‘matter’ as what satisfies the equations of physics. This definition is a logical construction rather than an appeal to a ‘stuff’. Mind can similarly be defined as ‘some group or structure of events’. Russell theorized that ‘the grouping must be effected by some relation which is characteristic of the sort of phenomena we wish to call “mental”’.[66] He used the example of memory, and suggested that we might define a mental event as one that remembers or is remembered. ‘Then the “mind” to which a given mental event belongs is the group of events connected with the given event by memory-chains, backwards or forwards.’[67]

This conclusion was echoed by Popper, who pointed out that:

… with Newton and … with Maxwell … the idea that there must be intuitively self-evident ultimate principles (such as, allegedly, those of a clockwork mechanism) behind explanation, had been exploded. Successive ‘self-evident’ intuitions as to the ‘true nature’ of matter had been shattered … What there was of value in essentialism—the desire to discover structures behind appearances, and the search for simple theories—was fully accommodated by the method of conjectural explanation.[68]

If we accept that it is science’s job to offer conjectural explanations rather than in terms of ‘stuffs’, then the insistence on physicalism so prevalent in the mind-sciences begins to seem a little dogmatic.

The first step, I propose, should be a relaxation of the insistence that we decide upon a particular ontology, and in particular monistic physicalism. Once this is done, the problem shifts to developing models that can enrich our understanding of the world in which we find ourselves, rather than worrying about ultimate principles that we can probably never directly know. This might sound overly positivistic; but I am not insisting that we should stop thinking about said principles or hidden entities, or even making use of them, just that we need not be enslaved bya certain view of how the world ‘must’ be.

A second potential advantage is that the problem of the causal redundancy of mental states can be either set aside or perhaps even abandoned. If we accept that the problem is not how an abstract, metaphorical ‘mental’ reduces or relates to an abstract and metaphorical ‘physical’, but rather how separate maps can be logically related, then the issue of causal redundancy seems to me to be reduced in importance. This is simply because we cannot always—or even often—reduce very general observations about the world (in this case, the bits we label ‘physical’ and ‘mental’) to simple logical equations.[69]

Whatever the neuroscience seems to say (and I will deal with this subsequently), it seems to me reasonable to accept that we have subjective experiences of a particular kind which includes apparent causal efficacy in the world, and that the task is or should not be to ‘reduce’ these experiences to a theoretical model but to understand better how they might relate to our abstract maps of the ‘physical’, which includes maps of our bodies and biology. But we should remember how partial and fragmentary these maps will be, even if they seem locally sophisticated and data-rich. If we acknowledge this, then the problem becomes how one might develop better and more inclusive maps than we have currently; but that is a task for epistemology.

1 Encyclopedia Brittanica, 1973 ed.

2 Penrose, 2004; Popper & Eccles, 1977.

3 Lewis, 1986; Gribbin, 1984.

4 Midgley, 2001.

5 Although this assertion is also metaphysical and can, and has, been challenged. Feyerabend stated that the objects different cultural traditions perceive can only be said to exist in the ‘same’ world if they are unified via some underlying universal theory, but that since this does not really exist, even in science, then we cannot claim that said objects really belong in the same ‘world’. Whilst I have not the space here to unpack the world/worlds debate, I will say that it becomes relevant, even pressing, when one moves from assuming that knowledge can be objective to assuming it to be intersubjective. I touch on this issue in chapter eleven and the book’s conclusion; some features of pluralism also suggest it. See also Feyerabend, 1987. Here, I accept the ‘one world’ idea for temporary convenience.

6 Lewis, 1986, p. 1.

7 Walter & Heckmann, 2003, p. 3.

8 See Koons & Bealer, 2010, for some philosophical critiques of physicalism.

9 Searle, 2007, p. 28.

10 See discussion in Collins & Pinch, 1982.

11 Gribbin, 1984; Henry, 2005; Rosenblum & Kuttner, 2006.

12 See Midgley, 1992, and Penrose, 1994, for critiques of these sorts of positions.

13 Stapp, 2007.

14 Bolender, 2003, p. 126.

15 From the Glossary pages of Koch’s website: http://www.klab.caltech.edu/~koch/ accessed on 29/09/09.

16 Rucker, 1997.

17 Wertheim, 1997.

18 Taton, 1964.

19 http://en.wikipedia.org/wiki/George_Berkeley accessed on 13/03/10.

20 Op. cit.

21 Borges, 1964. The story is titled ‘Tlon, Uqbar, Orbis Tertius’.

22 Marshall, 2005, p. 261.

23 Bostrom, 2003.

24 For example, Henry, 2005; Barrow & Tipler, 1986; but see Midgley, 1992, for a critical discussion of these theories.

25 Discussed in Blackmore, 2005.

26 Chalmers, 1996, proposes a form of substance-dualistic pansychism that is not really materialistic, although it seems causally inert.

27 Bennett & Hacker, 2003, chapter thirteen.

28 Bennett & Hacker, 2003, p. 357.

29 Dennett, 1991; Churchland, 1995.

30 Feyerabend, 1963a; 1963b.

31 Feyerabend, 1975, chapter thirteen.

32 Popper & Eccles, 1977; Daniels, 2005.

33 See Barrow & Tipler, 1986, pp. 195–205, for an overview of de Chardin’s thoughts; Wilber, 2000.

34 Popper & Eccles, 1977, p. 69.

35 See also the discussion in chapter twelve.

36 See the summary of teleological arguments in Barrow & Tipler, 1986; Sheldrake, 1988; Sahtouris, 1999.

37 Pauen, Staudacher & Walter, 2006, p. 8.

38 Wegner, 2002.

39 Carter, 2002.

40 Libet, 2004.

41 Carter, 2002, suggests this.

42 Gould & Lewontin, 1979.

43 Midgley, 2001.

44 Heil, 2004.

45 Pat Churchland in interview with Susan Blackmore. Blackmore, 2005, p. 55.

46 Heil, 2004; Popper & Eccles, 1977.

47 Similar arguments are made by both Heil and Popper (op. cit.)

48 Koons & Bealer, 2010; Raymont, 2003; Heil, 2004.

49 I would include the theories of both Chalmers, 1996, and Velmans, 2000, in this observation.

50 Blackmore, 2003, p. 13.

51 Popper & Eccles, 1977.

52 Braude, 1987.

53 Beloff, 2002.

54 Blackmore, 1993; Gauld, 1982.

55 Braude, 1981, p. 54.

56 Kelly et al., 2007.

57 Sagan, 1995. The phenomena were; the ganzfeld telepathy experiments, the micro-psychokinesis experiments, and the evidence that some young children have apparent memories and birthmarks from previous lives.

58 Popper & Eccles, 1977.

59 Penrose, 2004, p. 15.

60 Searle, 2007, p. 23.

61 Searle, 2007, p. 23.

62 Penrose, 2004, p. 15.

63 See Jones, 1982, for a discussion along these lines.

64 Russell, 1946/2004, p. 598.

65 Marshall, 2005.

66 Russell, 1946/2004, p. 598.

67 Op. cit., p. 598.

68 Popper & Eccles, 1977, p. 193.

69 This implies that thought experiments like the ‘Mary’ colour scientist are rather less useful in determining whether physicalism ‘is’ true than has been previously assumed. These sorts of arguments, although clever, strike me as akin to the esoteric debates in medieval scholasticism. I do not think they really resolve anything, simply because they assume a specificity in the terms like ‘physical’ and ‘mental’ that doesn’t really exist. See Beaton, 2005, for a summary of said arguments.