The hard problem of consciousness is the problem of explaining why and how humans have
qualia
In philosophy of mind, qualia ( or ; singular form: quale) are defined as individual instances of subjective, conscious experience. The term ''qualia'' derives from the Latin neuter plural form (''qualia'') of the Latin adjective '' quālis'' () ...
or
phenomenal
A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...
experiences. This is in contrast to the "easy problems" of explaining the physical systems that give us and other animals the ability to discriminate, integrate information, and so forth. These problems are seen as relatively easy because all that is required for their solution is to specify the mechanisms that perform such functions. Philosopher
David Chalmers
David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Universi ...
writes that even once we have solved all such problems about the brain and experience, the hard problem will still persist.
The existence of a "hard problem" is controversial. It has been accepted by
philosophers of mind
A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...
Colin McGinn
Colin McGinn (born 10 March 1950) is a British philosopher. He has held teaching posts and professorships at University College London, the University of Oxford, Rutgers University, and the University of Miami.
McGinn is best known for his work ...
, and
Ned Block
Ned Joel Block (born 1942) is an American philosopher working in philosophy of mind who has made important contributions to the understanding of consciousness and the philosophy of cognitive science. He has been professor of philosophy and psych ...
Francisco Varela
Francisco Javier Varela García (September 7, 1946 – May 28, 2001) was a Chilean biologist, philosopher, cybernetician, and neuroscientist who, together with his mentor Humberto Maturana, is best known for introducing the concept of autopoiesi ...
,
Giulio Tononi
Giulio Tononi () is a neuroscientist and psychiatrist who holds the David P. White Chair in Sleep Medicine, as well as a Distinguished Chair in Consciousness Science, at the University of Wisconsin. He is best known for his Integrated Informati ...
, and
Christof Koch
Christof Koch ( ; born November 13, 1956) is a German-American neurophysiologist and computational neuroscientist best known for his work on the neural basis of consciousness. He is the president and chief scientist of the Allen Institute for B ...
. However, its existence is disputed by philosophers of mind such as
Daniel Dennett
Daniel Clement Dennett III (born March 28, 1942) is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relat ...
,
Massimo Pigliucci
Massimo Pigliucci (; born January 16, 1964) is Professor of Philosophy at the City College of New York, former co-host of the '' Rationally Speaking Podcast'', and former editor in chief for the online magazine ''Scientia Salon''. He is a critic o ...
,
Thomas Metzinger
Thomas Metzinger (born 12 March 1958) is a German philosopher and professor of theoretical philosophy at the Johannes Gutenberg University of Mainz. , he is an Adjunct Fellow at the Frankfurt Institute for Advanced Studies, a co-founder of thGe ...
,
Patricia Churchland
Patricia Smith Churchland (born 16 July 1943) is a Canadian-American analytic philosopher noted for her contributions to neurophilosophy and the philosophy of mind. She is UC President's Professor of Philosophy Emerita at the University of Calif ...
Anil Seth
Anil Kumar Seth is a British professor of Cognitive and Computational Neuroscience at the University of Sussex.
Early life and education
Seth was born in England. His father, Bhola Seth, obtained a BSc from Allahabad University in 1945, befor ...
, and
Antonio Damasio
Antonio Damasio ( pt, António Damásio) is a Portuguese-American neuroscientist. He is currently the David Dornsife Chair in Neuroscience, as well as Professor of Psychology, Philosophy, and Neurology, at the University of Southern California, ...
.
Overview
David Chalmers
David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Universi ...
first formulated the hard problem in his paper "Facing up to the problem of consciousness" (1995) and expanded upon it in his book ''
The Conscious Mind
''The Conscious Mind: In Search of a Fundamental Theory'' was published in 1996, and is the first book written by David Chalmers, an Australian philosopher specialising in philosophy of mind. Though the book has been greatly influential, Chalmer ...
'' (1996). His works have proven to be provocative. Some, such as David Lewis and
Steven Pinker
Steven Arthur Pinker (born September 18, 1954) is a Canadian-American cognitive psychologist, psycholinguist, popular science author, and public intellectual. He is an advocate of evolutionary psychology and the computational theory of mind.
P ...
, have praised Chalmers for his argumentative rigour and "impeccable clarity". Others, such as
Daniel Dennett
Daniel Clement Dennett III (born March 28, 1942) is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relat ...
and
Patricia Churchland
Patricia Smith Churchland (born 16 July 1943) is a Canadian-American analytic philosopher noted for her contributions to neurophilosophy and the philosophy of mind. She is UC President's Professor of Philosophy Emerita at the University of Calif ...
, believe that the hard problem is best seen as a collection of easy problems and will be solved through further analysis of the brain and behaviour.
Consciousness is an ambiguous term. It can be used to mean self consciousness, awareness, the state of being awake, and so on. Chalmers uses
Thomas Nagel
Thomas Nagel (; born July 4, 1937) is an American philosopher. He is the University Professor of Philosophy and Law Emeritus at New York University, where he taught from 1980 to 2016. His main areas of philosophical interest are legal philosophy, ...
's definition of consciousness: ''the feeling of what it is like to be something.'' Consciousness, in this sense, is synonymous with ''experience.''
Chalmers' formulation
The problem of consciousness, Chalmers argues, is two problems: the ''easy problems'' and the ''hard problem''.
Easy problems
The easy problems are problems concerned with behaviour, and mechanistic analysis of the relevant neural processes that accompany that behaviour. Examples of these include how sensory systems work, how such data is processed in the brain, how that data influences behaviour or verbal reports, the neural basis of thought and emotion, and so on. These are problems that can be analyzed through "structures and functions".
Chalmers' use of the word ''easy'' is "tongue-in-cheek". As Steven Pinker puts it, they are about as easy as going to Mars or curing cancer. "That is, scientists more or less know what to look for, and with enough brainpower and funding, they would probably crack it in this century." The easy problems are amenable to reductive inquiry. They are a
logical consequence
Logical consequence (also entailment) is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically ''follows from'' one or more statements. A valid logical argument is on ...
of lower level facts about the world, similar to how a clock's ability to tell time is a logical consequence of its clockwork and structure, or a hurricane is a logical consequence of the structures and functions of certain weather patterns. A clock, a hurricane, and the easy problems, are all the sum of their parts (as are most things).
Hard problem
The hard problem, in contrast, is the problem of ''why'' and ''how'' those processes are accompanied by experience. It may further include the question of why these processes are accompanied by this or that particular experience, rather than some other kind of experience. In other words, the hard problem is the problem of explaining why certain mechanisms are accompanied by conscious experience. For example, why should neural processing in the brain lead to the felt sensations of, say, feelings of hunger? And why should those neural firings lead to feelings of hunger rather than some other feeling (such as, for example, feelings of thirst)?
Chalmers argues that it is conceivable that the relevant behaviours associated with hunger, or any other feeling, could occur even in the absence of that feeling. This suggests that experience is
irreducible
In philosophy, systems theory, science, and art, emergence occurs when an entity is observed to have properties its parts do not have on their own, properties or behaviors that emerge only when the parts interact in a wider whole.
Emergence ...
to physical systems such as the brain. This is the topic of the next section.
How the easy and hard problems are related
Chalmers believes that the hard problem is irreducible to the easy problems: solving the easy problems will not lead to a solution to the hard problems. This is because the easy problems are problems pertaining to the causal structure of the world, and the hard problem relates to consciousness, and facts about consciousness include facts that go beyond mere causal or structural description.
For example, take the experience of pain. Suppose one were to stub their foot and yelp. In this scenario, the easy problems are the various mechanistic explanations that involve the activity of one's nervous system and brain and its relation to the environment (such as the propagation of nerve signals from the toe to the brain, the processing of that information and how it leads to yelping, and so on). The hard problem is the question of why these mechanisms are accompanied by ''the feeling of pain'', or why these feelings of pain feel the particular way that they do. Chalmers argues that facts about the neural mechanisms of pain, and pain behaviours, do not lead to facts about conscious experience. Facts about conscious experience are, instead, further facts, not derivable from facts about the brain.In other words, Chalmers believes that solving the easy problems will not solve the hard problems. This is because the easy problems concern "structures and functions" whereas the hard problem contains "further facts" that are not reducible to structural or functional analysis. To return to the above example, this would mean that understanding the neural processing underpinning pain would not explain why those neural processes are accompanied by the feeling of pain. So even once one has explained all the relevant facts about neural processing, facts about what it is like to feel pain would remain unexplained.
Here's an example. If one were to program an AI system, the easy problems concern the problems related to discovering which algorithms are required in order to make this system produce intelligent outputs, or process information in the right sort of ways. The hard problem, in contrast, would concern questions as whether this AI system is conscious, what sort of conscious experiences it is privy to, and how and why this is the case. This suggests that solutions to the easy problem (such as how it the AI is programmed) do not automatically lead to solutions for the hard problem (concerning the potential consciousness of the AI).
Chalmers' diagnosis of the situation is that the easy facts concern structural and functional explanations, but facts about consciousness are not derivable from structural and functional facts. So structural and functional descriptions of the world do not fix facts about consciousness. This is because functions and structures of any sort could conceivably exist in the absence of experience. Alternatively, they could exist alongside a different set of experiences. For example, it is logically possible for a perfect replica of Chalmers to have no experience at all, or for it to have a different set of experiences (such as an inverted visible spectrum, so that the blue-yellow red-green axes of its visual field are run backwards).
The same cannot be said about clocks, hurricanes, or other physical things. In these cases, a structural or functional description is a complete description. A perfect replica of a clock is a clock, a perfect replica of a hurricane is a hurricane, and so on. The difference is that physical things are nothing more than their physical constituents. For example, water is nothing more than H2O molecules, and understanding everything about H2O molecules is to understand everything there is to know about water. But consciousness is not like this. Knowing everything there is to know about the brain, or any physical system, is not to know everything there is to know about consciousness. So consciousness, then, must not be purely physical.
Implications for physicalism
Chalmers' idea is significant because it contradicts
physicalism
In philosophy, physicalism is the metaphysical thesis that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical. Physicalism is a form of ontological monism—a "one substanc ...
(sometimes labelled
materialism
Materialism is a form of philosophical monism which holds matter to be the fundamental substance in nature, and all things, including mental states and consciousness, are results of material interactions. According to philosophical materiali ...
). This is the view that everything that exists is a physical or material thing, so everything can be reduced to microphysical things (such as subatomic particles and the interactions between them). For example, a desk is a physical thing, because it is nothing more than a complex arrangement of a large number of subatomic particles interacting in a certain way. According to physicalism, everything can be explained by appeal to its microphysical constituents, including consciousness. Chalmers' ''hard problem'' presents a
counterexample
A counterexample is any exception to a generalization. In logic a counterexample disproves the generalization, and does so rigorously in the fields of mathematics and philosophy. For example, the fact that "John Smith is not a lazy student" is a ...
to this view, since it suggests that consciousness cannot be reductively explained by appealing to its microphysical constituents. So if the hard problem is a real problem then physicalism must be false, and if physicalism is true then the hard problem must not be a real problem.
Though Chalmers rejects physicalism, he is still a naturalist.
Historical predecessors
The hard problem of consciousness has scholarly antecedents considerably earlier than Chalmers, as Chalmers himself has said.Chalmers (1997) states: "Any number of thinkers in the recent and distant past – including a number of contributors to this symposium – have recognized the particular difficulties of explaining consciousness and have tried to face up to them in various ways. All my paper really contributes is a catchy name, a minor reformulation of philosophically familiar points, and a specific approach to dealing with them." Among others, thinkers who have made arguments similar to Chalmers' formulation of the hard problem include
Isaac Newton
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a "natural philosopher"), widely recognised as one of the grea ...
,
John Locke
John Locke (; 29 August 1632 – 28 October 1704) was an English philosopher and physician, widely regarded as one of the most influential of Age of Enlightenment, Enlightenment thinkers and commonly known as the "father of liberalism ...
,
Gottfried Wilhelm Leibniz
Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of mathema ...
,
John Stuart Mill
John Stuart Mill (20 May 1806 – 7 May 1873) was an English philosopher, political economist, Member of Parliament (MP) and civil servant. One of the most influential thinkers in the history of classical liberalism, he contributed widely to ...
, and
Thomas Henry Huxley
Thomas Henry Huxley (4 May 1825 – 29 June 1895) was an English biologist and anthropologist specialising in comparative anatomy. He has become known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.
The storie ...
. Likewise, Asian philosophers like
Dharmakirti
Dharmakīrti (fl. c. 6th or 7th century; Tibetan: ཆོས་ཀྱི་གྲགས་པ་; Wylie: ''chos kyi grags pa''), was an influential Indian Buddhist philosopher who worked at Nālandā.Tom Tillemans (2011)Dharmakirti Stanford ...
and
Guifeng Zongmi
Guifeng Zongmi () (780–1 February 841) was a Tang dynasty Buddhist scholar and bhikkhu, installed as fifth patriarch of the Huayan school as well as a patriarch of the Heze school of Southern Chan Buddhism. He wrote a number of works on the ...
discussed the problem of how consciousness arises from unconscious matter.
Commentary on the problem's explanatory targets
The philosopher Raamy Majeed argued in 2016 that the hard problem is, in fact, associated with two "explanatory targets":
# QPhysical processing gives rise to experiences with a phenomenal character.
# Our phenomenal qualities are thus-and-so.
The first fact concerns the relationship between the physical and the phenomenal (i.e., how and why are some physical states
felt
Felt is a textile material that is produced by matting, condensing and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood ...
states), whereas the second concerns the very nature of the phenomenal itself (i.e., what does the felt state feel like?).
Wolfgang Fasching argues that the hard problem is not about qualia, but about pure what-it-is-like-ness of experience in Nagel's sense, about the very givenness of any phenomenal contents itself:
Today there is a strong tendency to simply ''equate'' consciousness with the qualia. Yet there is clearly something not quite right about this. The "itchiness of itches" and the "hurtfulness of pain" are qualities we are conscious ''of''. So philosophy of mind tends to treat consciousness as if it consisted simply of the contents of consciousness (the phenomenal qualities), while it really is precisely ''consciousness'' of contents, the very givenness of whatever is subjectively given. And therefore the problem of consciousness does not pertain so much to some alleged "mysterious, nonpublic objects", i.e. objects that seem to be only "visible" to the respective subject, but rather to the nature of "seeing" itself (and in today’s philosophy of mind astonishingly little is said about the latter).
Related concepts
"What Is It Like to Be a Bat?"
The philosopher Thomas Nagel posited in his 1974 paper "What Is It Like to Be a Bat?" that experiences are essentially subjective (accessible only to the individual undergoing them—i.e., felt only by the one feeling them), while physical states are essentially objective (accessible to multiple individuals). So at this stage, he argued, we have no idea what it could even mean to claim that an essentially subjective state just ''is'' an essentially non-subjective state (i.e., how and why a felt state is just a functional state). In other words, we have no idea of what reductivism really amounts to. To explain conscious experience within the physicalist framework requires an adequate account. He believes this is impossible, because "every subjective phenomenon is essentially connected with a single point of view, and it seems inevitable that an objective, physical theory will abandon that point of view."
Explanatory gap
In 1983, the philosopher Joseph Levine proposed that there is an ''explanatory gap'' between our understanding of the physical world and our understanding of consciousness.Levine, J. 1983. “Materialism and qualia: the explanatory gap”. Pacific Philosophical Quarterly, 64: 354-361.
Levine's argument is directed at the notion that conscious states are reducible neuronal or brain states. Levine famously uses the example of pain (as an example of a conscious state) is reducible to the firing of c-fibers (a kind of nerve cell). The difficulty is as follows: even if consciousness is physical, it is not clear which physical states correspond to which conscious states. The bridges between the two levels of description will be
contingent
Contingency or Contingent may refer to:
* Contingency (philosophy), in philosophy and logic
* Contingency plan, in planning
* Contingency table, in statistics
* Contingency theory, in organizational theory
* Contingency theory (biology) in evoluti ...
, rather than necessary. This is significant because in most contexts, relating two scientific levels of descriptions (such as physics and chemistry) is done with the assurance of necessary connections between the two theories (for example, chemistry follows with necessity from physics).
Levine illustrates this point with the following thought experiment. Suppose that humanity were to encounter an alien species, and suppose it is known that the aliens do not have any c-fibers. Even if one knows this, it is not obvious that the aliens do not feel pain: that would remain an open question. This is because the fact that aliens do not have c-fibers does not entail that they do not feel pain (in other words, feelings of pain do not follow with logical necessity from the firing of c-fibers. Levine thinks this and similar thought experiments show that there is an explanatory gap between consciousness and the physical world: even if consciousness is reducible to physical things, consciousness cannot be explained in terms of physical things, because the link between physical things and consciousness is contingent link.
Levine does not think that the explanatory gap means that consciousness is not physical: he is open to the idea that the explanatory gap is only an
epistemological
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Episte ...
problem for physicalism. In contrast, Chalmers thinks that the hard problem of consciousness does show that consciousness is not physical.
Philosophical zombies
Philosophical zombies are a thought experiment commonly used in discussions of the hard problem. They are hypothetical beings physically identical to humans but lack conscious experience. Philosophers such as Chalmers, Joseph Levine, and Francis Kripke take zombies as impossible within the bounds of nature but possible within the bounds of logic. This would imply that facts about experience are not logically entailed by the "physical" facts. Therefore, consciousness is irreducible. In Chalmers' words, "after God (hypothetically) created the world, he had more work to do."
David Chalmers
David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Universi ...
(1996) ''The Conscious Mind: In Search of a Fundamental Theory'', pp. 153–6. Oxford University Press, New York, (Pbk.) Daniel Dennett, a philosopher of mind, has criticised the field's use of "the zombie hunch" which he deems an "embarrassment" that ought to "be dropped like a hot potato".Dennett, Daniel; commentary on T. Moody, O. Flanagan and T. Polger. The Unimagined Preposterous of Zombies , ''Journal of Consciousness Studies'' vol. 2, no. 4, 1995, pp. 322–326.
Knowledge argument
The knowledge argument, also known as ''Mary's Room'', is another common thought experiment. It centres around a hypothetical neuroscientist named Mary. She has lived her whole life in a black and white room and has never seen colour before. She also happens to know everything there is to know about the brain and colour perception. Chalmers believes that if Mary were to see the colour red for the first time that she would gain new knowledge of the world. That means knowledge of what red looks like is distinct from knowledge of the brain or visual system. In other words knowledge of what red looks like ''is irreducible'' to knowledge of the brain or nervous system; therefore, experience is irreducible to the functioning of the brain or nervous system. Others disagree, saying the same could be said about Mary knowing everything there is to know about bikes and riding one for the first time, or swimming, etc. Elsewhere,
Thomas Nagel
Thomas Nagel (; born July 4, 1937) is an American philosopher. He is the University Professor of Philosophy and Law Emeritus at New York University, where he taught from 1980 to 2016. His main areas of philosophical interest are legal philosophy, ...
has put forward a "speculative proposal" of devising a language that could "explain to a person blind from birth what it is like to see." If such a language is possible then the force of the knowledge argument may be undercut.
Philosophical responses
Chalmers' formulation of the hard problem of consciousness has provoked considerable debate within
philosophy of mind
Philosophy of mind is a branch of philosophy that studies the ontology and nature of the mind and its relationship with the body. The mind–body problem is a paradigmatic issue in philosophy of mind, although a number of other issues are addre ...
as well as scientific research. Some responses accept the problem as real and seek to develop a theory of consciousness' place in the world that can solve it, while others seek to show that the apparent hard problem as distinct from the easy problems dissolves upon analysis. A third response has been to accept the hard problem as real but deny human cognitive faculties can solve it.
According to a 2020 Philpapers survey, 29.72% of philosophers surveyed believe that the hard problem does not exist, while 62.42% of philosophers surveyed believe that the hard problem is a genuine problem.
Proposed solutions
Different solutions have been proposed to the hard problem of consciousness. One of these, weak reductionism, is the view that while there is an epistemic hard problem of consciousness that will not be solved directly by scientific progress, this is due to our conceptualization, not an
ontological
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exi ...
gap. A traditional solution gaining renewed popularity is
idealism
In philosophy, the term idealism identifies and describes metaphysical perspectives which assert that reality is indistinguishable and inseparable from perception and understanding; that reality is a mental construct closely connected to ide ...
, according to which consciousness is fundamental and not simply an emergent property of matter. It is claimed that this avoids the hard problem entirely. Dualism views consciousness as either a non-physical substance separate from the brain or a non-physical
property
Property is a system of rights that gives people legal control of valuable things, and also refers to the valuable things themselves. Depending on the nature of the property, an owner of property may have the right to consume, alter, share, r ...
of the physical brain. Meanwhile,
panpsychism
In the philosophy of mind, panpsychism () is the view that the mind or a mindlike aspect is a fundamental and ubiquitous feature of reality. It is also described as a theory that "the mind is a fundamental feature of the world which exists thro ...
and
neutral monism
Neutral monism is an umbrella term for a class of metaphysical theories in the philosophy of mind. These theories reject the dichotomy of mind and matter, believing the fundamental nature of reality to be neither mental nor physical; in other words ...
, broadly speaking, view consciousness as intrinsic to matter.
Weak reductionism
There is a split among those subscribing to reductive materialism between those who hold there is no hard problem of consciousness—"strong reductionists" (see below)—and "weak reductionists" who, while remaining
ontologically
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exis ...
committed to
physicalism
In philosophy, physicalism is the metaphysical thesis that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical. Physicalism is a form of ontological monism—a "one substanc ...
, accept an epistemic hard problem of consciousness. Put differently, weak reductionists believe there is a gap between two ways of knowing (introspection and neuroscience) that will not be resolved by understanding all the underlying neurobiology, but still believe that consciousness and neurobiology are one and the same in reality. For example, Joseph Levine, who formulated the notion of the ''explanatory gap'' (see above), states: "The explanatory gap argument doesn't demonstrate a gap in nature, but a gap in our understanding of nature." He nevertheless contends that a full scientific understanding will not close the gap, and that analogous gaps do not exist for other identities in nature, such as that between water and H2O. The philosophers
Ned Block
Ned Joel Block (born 1942) is an American philosopher working in philosophy of mind who has made important contributions to the understanding of consciousness and the philosophy of cognitive science. He has been professor of philosophy and psych ...
and
Robert Stalnaker
Robert Culp Stalnaker (born 1940) is an American philosopher who is Laurance S. Rockefeller Professor Emeritus of Philosophy at the Massachusetts Institute of Technology. He is a Fellow of the American Academy of Arts and Sciences and a Correspond ...
agree that facts about what a conscious experience is like to the one experiencing it cannot be deduced from knowing all the facts about the underlying physiology, but by contrast argue that such gaps of knowledge are also present in many other cases in nature, such as the distinction between water and H2O.
To explain why these two ways of knowing (i.e. third-person scientific observation and first-person introspection) yield such different understandings of consciousness, weak reductionists often invoke the ''phenomenal concepts strategy'', which argues the difference stems from our inaccurate
phenomenal
A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...
concepts (i.e., how we think about consciousness), not the nature of consciousness itself. Thus, the hard problem of consciousness stems only from a dualism of concepts, not a dualism of properties or substances (see next section).
Dualism
Dualism is the view that the mind is irreducible to the physical body. There are multiple dualist accounts of the causal relationship between the mental and the physical, of which interactionism and epiphenomenalism are the most common today. Interactionism posits that the mental and physical causally impact one another, and is associated with the thought of
René Descartes
René Descartes ( or ; ; Latinized: Renatus Cartesius; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and science. Mathem ...
(1596–1650). Epiphenomalism, by contrast, holds the mental is causally dependent on the physical, but does not in turn causally impact it. In contemporary philosophy, interactionism has been defended by philosophers including
Martine Nida-Rümelin
Martine Nida-Rümelin (born 1957 in Munich) is a philosopher.
Biography
Nida-Rümelin studied philosophy, psychology, mathematics and political science at the University of Munich.
In her doctoral thesis, she discusses the knowledge argument, ...
, while epiphenomenalism has been defended by philosophers including Frank Jackson (although Jackson later changed his stance to physicalism). Chalmers has also defended versions of both positions as plausible. Traditional dualists such as Descartes believed the mental and the physical to be two separate substances, or fundamental types of entities (hence " substance dualism"); some more recent dualists, however, accept only one substance, the physical, but state it has both mental and physical
properties
Property is the ownership of land, resources, improvements or other tangible objects, or intellectual property.
Property may also refer to:
Mathematics
* Property (mathematics)
Philosophy and science
* Property (philosophy), in philosophy and ...
(hence "
property dualism
Property dualism describes a category of positions in the philosophy of mind which hold that, although the world is composed of just one kind of substance— the physical kind—there exist two distinct kinds of properties: physical properties ...
").
Panpsychism and neutral monism
In its most basic form, panpsychism holds that all physical entities have minds (though its proponents in fact take more qualified positions), while neutral monism, in at least some variations, holds that entities are composed of a substance with mental and physical aspects—and is thus sometimes described as a type of panpsychism. Forms of panpsychism and neutral monism were defended in the early twentieth century by the psychologist
William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher, historian, and psychologist, and the first educator to offer a psychology course in the United States.
James is considered to be a leading thinker of the lat ...
,There has been debate over how best to characterize James' position. The ''Stanford Encyclopedia of Philosophy'' states: "James’s commitment to panpsychism remains somewhat controversial, since he also advanced a cogent set of objections against a version of the view, which he labelled the 'mind dust' theory, in chapter six of The Principles of Psychology (
890
__NOTOC__
Year 890 ( DCCCXC) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar.
Events
By place
Europe
* The Frankish nobles, who have ruled Provence in anarchy (since 887), declare L ...
1981). These objections are the inspiration for the so-called 'combination problem', around which much of the twenty first century literature on panpsychism focuses." the philosopher
Alfred North Whitehead
Alfred North Whitehead (15 February 1861 – 30 December 1947) was an English mathematician and philosopher. He is best known as the defining figure of the philosophical school known as process philosophy, which today has found applicat ...
, the physicist
Arthur Eddington
Sir Arthur Stanley Eddington (28 December 1882 – 22 November 1944) was an English astronomer, physicist, and mathematician. He was also a philosopher of science and a populariser of science. The Eddington limit, the natural limit to the lumin ...
, and the philosopher
Bertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British mathematician, philosopher, logician, and public intellectual. He had a considerable influence on mathematics, logic, set theory, linguistics, ...
, and interest in these views has been revived in recent decades by philosophers including
Thomas Nagel
Thomas Nagel (; born July 4, 1937) is an American philosopher. He is the University Professor of Philosophy and Law Emeritus at New York University, where he taught from 1980 to 2016. His main areas of philosophical interest are legal philosophy, ...
,
Galen Strawson
Galen John Strawson (born 1952) is a British analytic philosopher and literary critic who works primarily on philosophy of mind, metaphysics (including free will, panpsychism, the mind-body problem, and the self), John Locke, David Hume, ...
, and David Chalmers. Chalmers describes his overall view as "naturalistic dualism", but he says panpsychism is in a sense a form of physicalism, as does Strawson. Proponents of panpsychism argue it solves the hard problem of consciousness parsimoniously by making consciousness a fundamental feature of reality.
Objective idealism and cosmopsychism
Objective idealism
Objective idealism is a form of metaphysical idealism that accepts Naïve realism (the view that empirical objects exist objectively) but rejects epiphenomenalist materialism (according to which the mind and spiritual values have emerged due to ...
and
cosmopsychism
In the philosophy of mind, panpsychism () is the view that the mind or a mindlike aspect is a fundamental and ubiquitous feature of reality. It is also described as a theory that "the mind is a fundamental feature of the world which exists thro ...
consider mind or consciousness to be the fundamental substance of the universe. Proponents claim that this approach is immune to both the hard problem of consciousness and the
combination problem
In the philosophy of mind, panpsychism () is the view that the mind or a mindlike aspect is a fundamental and ubiquitous feature of reality. It is also described as a theory that "the mind is a fundamental feature of the world which exists thro ...
that affects panpsychism.
From an idealist perspective, matter is a representation or image of mental processes, and supporters suggest that this avoids the problems associated with the materialist view of mind as an emergent property of a physical brain.
Critics of this approach point out that you then have a decombination problem, in terms of explaining individual subjective experience. In response, Bernardo Kastrup claims that nature has already hinted at a mechanism for this in the condition
Dissociative identity disorder
Dissociative identity disorder (DID), better known as multiple personality disorder or multiple personality syndrome, is a mental disorder characterized by the presence of at least two distinct and relatively enduring personality states.
The di ...
(previously known as Multiple Personality Disorder). Kastrup proposes dissociation as an example from nature showing that multiple minds with their own individual subjective experience could develop within a single universal mind.
Cognitive psychologist
Donald D. Hoffman
Donald David Hoffman (born December 29, 1955) is an American cognitive psychologist and popular science author. He is a professor in the Department of Cognitive Sciences at the University of California, Irvine, with joint appointments in the D ...
uses a mathematical model based around conscious agents, within a fundamentally conscious universe, to support conscious realism as a description of nature that falls within the objective idealism approaches to the hard problem: "The objective world, i.e., the world whose existence does not depend on the perceptions of a particular conscious agent, consists entirely of conscious agents."
David Chalmers has said this form of idealism is one of "the handful of promising approaches to the mind–body problem."
Rejection of the problem
Many philosophers have disputed that there is a hard problem of consciousness distinct from what Chalmers calls the easy problems of consciousness. Some among them, who are sometimes termed ''strong reductionists'', hold that
phenomenal consciousness
Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scient ...
(i.e., conscious experience) does exist but that it can be fully understood as reducible to the brain. Others maintain that phenomenal consciousness can be eliminated from the scientific picture of the world, and hence are called '' eliminative materialists'' or ''eliminativists''.
Strong reductionism
Broadly, strong reductionists accept that conscious experience is real but argue it can be fully understood in functional terms as an emergent property of the material brain. In contrast to weak reductionists (see above), strong reductionists reject ideas used to support the existence of a hard problem (that the same functional organization could exist without consciousness, or that a blind person who understood vision through a textbook would not know everything about sight) as simply mistaken intuitions.
A notable family of strong reductionist accounts are the
higher-order theories of consciousness
Higher-order theories of consciousness postulate that consciousness consists in perceptions or thoughts about first-order mental states. In particular, phenomenal consciousness is thought to be higher-order representation of perceptual or quasi-pe ...
. In 2005, the philosopher Peter Carruthers wrote about "recognitional concepts of experience", that is, "a capacity to recognize type of experience when it occurs in one's own mental life," and suggested that such a capacity could explain phenomenal consciousness without positing qualia. On the higher-order view, since consciousness is a representation, and representation is fully functionally analyzable, there is no hard problem of consciousness.
The philosophers Glenn Carruthers and Elizabeth Schier said in 2012 that the main arguments for the existence of a hard problem—
philosophical zombies
A philosophical zombie or p-zombie argument is a thought experiment in philosophy of mind that imagines a hypothetical being that is physically identical to and indistinguishable from a normal person but does not have conscious experience, qual ...
,
Mary's room
The knowledge argument (also known as Mary's room or Mary the super-scientist) is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986). The experim ...
, and Nagel's bats—are only persuasive if one already assumes that "consciousness must be independent of the structure and function of mental states, i.e. that there is a hard problem." Hence, the arguments
beg the question
In classical rhetoric and logic, begging the question or assuming the conclusion (Latin: ') is an informal fallacy that occurs when an argument's premises assume the truth of the conclusion, instead of supporting it.
For example:
* "Green is ...
. The authors suggest that "instead of letting our conclusions on the thought experiments guide our theories of consciousness, we should let our theories of consciousness guide our conclusions from the thought experiments."
The philosopher
Massimo Pigliucci
Massimo Pigliucci (; born January 16, 1964) is Professor of Philosophy at the City College of New York, former co-host of the '' Rationally Speaking Podcast'', and former editor in chief for the online magazine ''Scientia Salon''. He is a critic o ...
argued in 2013 that the hard problem is misguided, resulting from a "category mistake". He said: "Of course an explanation isn't the same as an experience, but that's because the two are completely independent categories, like colors and triangles. It is obvious that I cannot experience what it is like to be you, but I can potentially have a complete explanation of how and why it is possible to be you."
In 2017, the philosopher Marco Stango, in a paper on
John Dewey
John Dewey (; October 20, 1859 – June 1, 1952) was an American philosopher, psychologist, and educational reformer whose ideas have been influential in education and social reform. He was one of the most prominent American scholars in the f ...
's approach to the problem of consciousness (which preceded Chalmers' formulation of the hard problem by over half a century), noted that Dewey's approach would see the hard problem as the consequence of an unjustified assumption that feelings and functional behaviors are not the same physical process: "For the Deweyan philosopher, the 'hard problem' of consciousness is a 'conceptual fact' only in the sense that it is a : the mistake of failing to see that the physical can be had as an episode of immediate sentiency."
The philosopher
Thomas Metzinger
Thomas Metzinger (born 12 March 1958) is a German philosopher and professor of theoretical philosophy at the Johannes Gutenberg University of Mainz. , he is an Adjunct Fellow at the Frankfurt Institute for Advanced Studies, a co-founder of thGe ...
likens the hard problem of consciousness to
vitalism
Vitalism is a belief that starts from the premise that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things." Wher ...
, a formerly widespread view in biology which was not so much solved as abandoned. Brian Jonathan Garrett has also argued that the hard problem suffers from flaws analogous to those of vitalism.
Eliminative materialism
Eliminative materialism
Eliminative materialism (also called eliminativism) is a materialist position in the philosophy of mind. It is the idea that majority of the mental states in folk psychology do not exist. Some supporters of eliminativism argue that no coherent ...
or eliminativism is the view that many or all of the
mental states
A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definiti ...
used in
folk psychology
In philosophy of mind and cognitive science, folk psychology, or commonsense psychology, is a human capacity to explain and predict the behavior and mental state of other people. Processes and items encountered in daily life such as pain, pleasure ...
(i.e., common-sense ways of discussing the mind) do not, upon scientific examination, correspond to real brain mechanisms. While
Patricia Churchland
Patricia Smith Churchland (born 16 July 1943) is a Canadian-American analytic philosopher noted for her contributions to neurophilosophy and the philosophy of mind. She is UC President's Professor of Philosophy Emerita at the University of Calif ...
and
Paul Churchland
Paul Montgomery Churchland (born October 21, 1942) is a Canadian philosopher known for his studies in neurophilosophy and the philosophy of mind. After earning a Ph.D. from the University of Pittsburgh under Wilfrid Sellars (1969), Churchland ros ...
have famously applied eliminative materialism to
propositional attitudes
A propositional attitude is a mental state held by an agent toward a proposition.
Linguistically, propositional attitudes are denoted by a verb (e.g. "believed") governing an embedded "that" clause, for example, 'Sally believed that she had won ...
, philosophers including
Daniel Dennett
Daniel Clement Dennett III (born March 28, 1942) is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relat ...
,
Georges Rey
Georges Leon Rey (born 1945) is an American philosopher. He is a professor of philosophy at the University of Maryland.
Biography
Rey received a doctoral degree in philosophy from Harvard University in 1978. His thesis was titled ''The possibi ...
qualia
In philosophy of mind, qualia ( or ; singular form: quale) are defined as individual instances of subjective, conscious experience. The term ''qualia'' derives from the Latin neuter plural form (''qualia'') of the Latin adjective '' quālis'' () ...
or
phenomenal consciousness
Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scient ...
(i.e., conscious experience). On their view, it is mistaken not only to believe there is a hard problem of consciousness, but to believe consciousness exists at all (in the sense of phenomenal consciousness).
Dennett asserts that the so-called "hard problem" will be solved in the process of solving what Chalmers terms the "easy problems". He compares consciousness to stage magic and its capability to create extraordinary illusions out of ordinary things. To show how people might be commonly fooled into overstating the accuracy of their introspective abilities, he describes a phenomenon called
change blindness
Change blindness is a perceptual phenomenon that occurs when a change in a visual stimulus is introduced and the observer does not notice it. For example, observers often fail to notice major differences introduced into an image while it flickers ...
, a visual process that involves failure to detect scenery changes in a series of alternating images. He accordingly argues that consciousness need not be what it seems to be based on introspection. To address the question of the hard problem, or how and why physical processes give rise to experience, Dennett states that the phenomenon of having experience is nothing more than the performance of functions or the production of behavior, which can also be referred to as the easy problems of consciousness. Thus, Dennett argues that the hard problem of experience is included among—not separate from—the easy problems, and therefore they can only be explained together as a cohesive unit.
In 2013, the philosopher Elizabeth Irvine argued that both science and folk psychology do not treat
mental state
A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definiti ...
s as having phenomenal properties, and therefore "the hard problem of consciousness may not be a genuine problem for non-philosophers (despite its overwhelming obviousness to philosophers), and questions about consciousness may well 'shatter' into more specific questions about particular capacities."
In 2016, Frankish proposed the term " illusionism" as superior to "eliminativism" for describing the position that phenomenal consciousness is an illusion. In the introduction to his paper, he states: "Theories of consciousness typically address the hard problem. They accept that phenomenal consciousness is real and aim to explain how it comes to exist. There is, however, another approach, which holds that phenomenal consciousness is an illusion and aims to explain why it seems to exist." After offering arguments in favor and responding to objections, Frankish concludes that illusionism "replaces the hard problem with the illusion problem—the problem of explaining how the illusion of phenomenality arises and why it is so powerful."
In 2022,
Jacy Reese Anthis
Jacy Reese Anthis ( ; born December 16, 1992), who has written under the name Jacy Reese, is an American social scientist, writer and co-founder of the Sentience Institute with Kelly Witwicki. He previously worked as a Senior Fellow at Sentien ...
published ''Consciousness Semanticism: A Precise Eliminativist Theory of Consciousness''. The consciousness semanticism position, a formulation of eliminative materialism, highlights semantic ambiguity in discussions of consciousness. Anthis argues that while many philosophers have engaged in "intuition jousting," we can instead approach the hard problem with "formal argumentation from precise semantics." On this view, there is no hard problem because consciousness does not exist as a property beyond what can be understood through logical and empirical analysis.
A complete illusionist theory of consciousness must include the description of a
mechanism
Mechanism may refer to:
* Mechanism (engineering), rigid bodies connected by joints in order to accomplish a desired force and/or motion transmission
*Mechanism (biology), explaining how a feature is created
*Mechanism (philosophy), a theory that ...
by which the apparently subjective aspect of consciousness is perceived and reported by people. Various philosophers and scientists have proposed possible theories. For example, in his book ''Consciousness and the Social Brain'' neuroscientist
Michael Graziano
Michael Steven Anthony Graziano (born May 22, 1967) is an American scientist and novelist who is currently a professor of Psychology and Neuroscience at Princeton University.attention schema theory, in which our perception of being conscious is merely an error in perception, held by brains which evolved to hold erroneous and incomplete models of their own internal workings, just as they hold erroneous and incomplete models of their own bodies and of the external world.
Other views
The philosopher
Peter Hacker
Peter Michael Stephan Hacker (born 15 July 1939) is a British philosopher.
His principal expertise is in the philosophy of mind, philosophy of language, and philosophical anthropology. He is known for his detailed exegesis and interpretatio ...
argues that the hard problem is misguided in that it asks how consciousness can emerge from matter, whereas in fact sentience emerges from the evolution of living organisms. He states: "The hard problem isn’t a hard problem at all. The really hard problems are the problems the scientists are dealing with. ..The philosophical problem, like all philosophical problems, is a confusion in the conceptual scheme." Hacker's critique extends beyond Chalmers and the hard problem and is directed against contemporary philosophy of mind and neuroscience more broadly. Along with the neuroscientist Max Bennett, he has argued that most of contemporary neuroscience remains implicitly dualistic in its conceptualizations and is predicated on the '' mereological fallacy'' of ascribing psychological concepts to the brain that can properly be ascribed only to the person as a whole. Hacker further states that "consciousness studies", as it exists today, is "literally a total waste of time":
The whole endeavour of the consciousness studies community is absurd—they are in pursuit of a chimera. They misunderstand the nature of consciousness. The conception of consciousness which they have is incoherent. The questions they are asking don't make sense. They have to go back to the drawing board and start all over again.
New mysterianism
New mysterianism
New mysterianism, or commonly just mysterianism, is a philosophical position proposing that the hard problem of consciousness cannot be resolved by humans. The unresolvable problem is how to explain the existence of qualia (individual instances o ...
, most significantly associated with the philosopher
Colin McGinn
Colin McGinn (born 10 March 1950) is a British philosopher. He has held teaching posts and professorships at University College London, the University of Oxford, Rutgers University, and the University of Miami.
McGinn is best known for his work ...
, proposes that the human mind, in its current form, will not be able to explain consciousness. McGinn draws on
Noam Chomsky
Avram Noam Chomsky (born December 7, 1928) is an American public intellectual: a linguist, philosopher, cognitive scientist, historian, social critic, and political activist. Sometimes called "the father of modern linguistics", Chomsky is ...
's distinction between problems, which are in principle solvable, and mysteries, which human cognitive faculties are unequipped to ever understand, and places the mind-body problem in the latter category. His position is that a naturalistic explanation does exist but that the human mind is cognitively closed to it due to its limited range of intellectual abilities. He cites
Jerry Fodor
Jerry Alan Fodor (; April 22, 1935 – November 29, 2017) was an American philosopher and the author of many crucial works in the fields of philosophy of mind and cognitive science. His writings in these fields laid the groundwork for the modu ...
's concept of the modularity of mind in support of cognitive closure.
While in McGinn's strong form, new mysterianism states that the relationship between consciousness and the material world can ''never'' be understood by the human mind, there are also weaker forms that argue it cannot be understood within existing paradigms but that advances in science or philosophy may open the way to other solutions (see above). The ideas of
Thomas Nagel
Thomas Nagel (; born July 4, 1937) is an American philosopher. He is the University Professor of Philosophy and Law Emeritus at New York University, where he taught from 1980 to 2016. His main areas of philosophical interest are legal philosophy, ...
and Joseph Levine fall into the second category. The cognitive psychologist
Steven Pinker
Steven Arthur Pinker (born September 18, 1954) is a Canadian-American cognitive psychologist, psycholinguist, popular science author, and public intellectual. He is an advocate of evolutionary psychology and the computational theory of mind.
P ...
has also endorsed this weaker version of the view, summarizing it as follows:
And then there is the theory put forward by philosopher Colin McGinn that our vertigo when pondering the Hard Problem is itself a quirk of our brains. The brain is a product of evolution, and just as animal brains have their limitations, we have ours. Our brains can't hold a hundred numbers in memory, can't visualize seven-dimensional space and perhaps can't intuitively grasp why neural information processing observed from the outside should give rise to subjective experience on the inside. This is where I place my bet, though I admit that the theory could be demolished when an unborn genius—a Darwin or Einstein of consciousness—comes up with a flabbergasting new idea that suddenly makes it all clear to us.
Relationship to scientific frameworks
Most neuroscientists and cognitive scientists believe that Chalmers' alleged hard problem will be solved in the course of solving what he terms the easy problems, although a significant minority disagrees.
Neural correlates of consciousness
Since 1990, researchers including the molecular biologist
Francis Crick
Francis Harry Compton Crick (8 June 1916 – 28 July 2004) was an English molecular biologist, biophysicist, and neuroscientist. He, James Watson, Rosalind Franklin, and Maurice Wilkins played crucial roles in deciphering the helical struc ...
and the neuroscientist
Christof Koch
Christof Koch ( ; born November 13, 1956) is a German-American neurophysiologist and computational neuroscientist best known for his work on the neural basis of consciousness. He is the president and chief scientist of the Allen Institute for B ...
have made significant progress toward identifying which neurobiological events occur concurrently to the experience of subjective consciousness. These postulated events are referred to as ''neural correlates of consciousness'' or NCCs. However, this research arguably addresses the question of ''which'' neurobiological mechanisms are linked to consciousness but not the question of ''why'' they should give rise to consciousness at all, the latter being the hard problem of consciousness as Chalmers formulated it. In "On the Search for the Neural Correlate of Consciousness", Chalmers said he is confident that, granting the principle that something such as what he terms global availability can be used as an indicator of consciousness, the neural correlates will be discovered "in a century or two". Nevertheless, he stated regarding their relationship to the hard problem of consciousness:
One can always ask why these processes of availability should give rise to consciousness in the first place. As yet we cannot explain why they do so, and it may well be that full details about the processes of availability will still fail to answer this question. Certainly, nothing in the standard methodology I have outlined answers the question; that methodology assumes a relation between availability and consciousness, and therefore does nothing to explain it. ..So the hard problem remains. But who knows: Somewhere along the line we may be led to the relevant insights that show why the link is there, and the hard problem may then be solved.
The neuroscientist and Nobel laureate
Eric Kandel
Eric Richard Kandel (; born Erich Richard Kandel, November 7, 1929) is an Austrian-born American medical doctor who specialized in psychiatry, a neuroscientist and a professor of biochemistry and biophysics at the College of Physicians and Surge ...
wrote that locating the NCCs would not solve the hard problem, but rather one of the so-called easy problems to which the hard problem is contrasted. Kandel went on to note Crick and Koch's suggestion that once the
binding problem The consciousness and binding problem is the problem of how objects, background and abstract or emotional features are combined into a single experience.
The binding problem refers to the overall encoding of our brain circuits for the combination o ...
—understanding what accounts for the unity of experience—is solved, it will be possible to solve the hard problem empirically. However, neuroscientist
Anil Seth
Anil Kumar Seth is a British professor of Cognitive and Computational Neuroscience at the University of Sussex.
Early life and education
Seth was born in England. His father, Bhola Seth, obtained a BSc from Allahabad University in 1945, befor ...
argued that emphasis on the so-called hard problem is a distraction from what he calls the "real problem": understanding the neurobiology underlying consciousness, namely the neural correlates of various conscious processes. This more modest goal is the focus of most scientists working on consciousness. Psychologist
Susan Blackmore
Susan Jane Blackmore (born 29 July 1951) is a British writer, lecturer, sceptic, broadcaster, and a Visiting Professor at the University of Plymouth. Her fields of research include memetics, parapsychology, consciousness, and she is best known ...
believes, by contrast, that the search for the neural correlates of consciousness is futile and itself predicated on an erroneous belief in the hard problem of consciousness.
Integrated information theory
Integrated information theory (IIT), developed by the neuroscientist and psychiatrist
Giulio Tononi
Giulio Tononi () is a neuroscientist and psychiatrist who holds the David P. White Chair in Sleep Medicine, as well as a Distinguished Chair in Consciousness Science, at the University of Wisconsin. He is best known for his Integrated Informati ...
in 2004 and more recently also advocated by Koch, is one of the most discussed models of consciousness in neuroscience and elsewhere. The theory proposes an
identity
Identity may refer to:
* Identity document
* Identity (philosophy)
* Identity (social science)
* Identity (mathematics)
Arts and entertainment Film and television
* ''Identity'' (1987 film), an Iranian film
* ''Identity'' (2003 film), ...
between consciousness and integrated information, with the latter item (denoted as Φ) defined mathematically and thus in principle measurable. The hard problem of consciousness, write Tononi and Koch, may indeed be intractable when working from matter to consciousness. However, because IIT inverts this relationship and works from phenomenological axioms to matter, they say it could be able to solve the hard problem. In this vein, proponents have said the theory goes beyond identifying human neural correlates and can be extrapolated to all physical systems. Tononi wrote (along with two colleagues):
While identifying the "neural correlates of consciousness" is undoubtedly important, it is hard to see how it could ever lead to a satisfactory explanation of what consciousness is and how it comes about. As will be illustrated below, IIT offers a way to analyze systems of mechanisms to determine if they are properly structured to give rise to consciousness, how much of it, and of which kind.
As part of a broader critique of IIT, Michael Cerullo suggested that the theory's proposed explanation is in fact for what he dubs (following
Scott Aaronson
Scott Joel Aaronson (born May 21, 1981) is an American theoretical computer scientist and David J. Bruton Jr. Centennial Professor of Computer Science at the University of Texas at Austin. His primary areas of research are quantum computing an ...
) the "Pretty Hard Problem" of methodically inferring which physical systems are conscious—but would not solve Chalmers' hard problem. "Even if IIT is correct," he argues, "it does not explain why integrated information generates (or is) consciousness." Chalmers agrees that IIT, if correct, would solve the "Pretty Hard Problem" rather than the hard problem.
cognitive architecture A cognitive architecture refers to both a theory about the structure of the human mind and to a computational instantiation of such a theory used in the fields of artificial intelligence (AI) and computational cognitive science. The formalized mod ...
and theory of consciousness proposed by the cognitive psychologist Bernard Baars in 1988. Baars explains the theory with the metaphor of a theater, with conscious processes represented by an illuminated stage. This theater integrates inputs from a variety of unconscious and otherwise autonomous networks in the brain and then broadcasts them to unconscious networks (represented in the metaphor by a broad, unlit "audience"). The theory has since been expanded upon by other scientists including cognitive neuroscientist Stanislas Dehaene.
In his original paper outlining the hard problem of consciousness, Chalmers discussed GWT as a theory that only targets one of the "easy problems" of consciousness. In particular, he said GWT provided a promising account of how information in the brain could become globally accessible, but argued that "now the question arises in a different form: why should global accessibility give rise to conscious experience? As always, this bridging question is unanswered." J. W. Dalton similarly criticized GWT on the grounds that it provides, at best, an account of the cognitive ''function'' of consciousness, and fails to explain its experiential aspect. By contrast, A. C. Elitzur argued: "While WTdoes not address the 'hard problem', namely, the very nature of consciousness, it constrains any theory that attempts to do so and provides important insights into the relation between consciousness and cognition."
For his part, Baars writes (along with two colleagues) that there is no hard problem of explaining
qualia
In philosophy of mind, qualia ( or ; singular form: quale) are defined as individual instances of subjective, conscious experience. The term ''qualia'' derives from the Latin neuter plural form (''qualia'') of the Latin adjective '' quālis'' () ...
over and above the problem of explaining causal functions, because qualia are entailed by neural activity and themselves causal. Dehaene, in his 2014 book '' Consciousness and the Brain'', rejected the concept of qualia and argued that Chalmers' "easy problems" of consciousness are actually the hard problems. He further stated that the "hard problem" is based only upon ill-defined intuitions that are continually shifting as understanding evolves:
Once our intuitions are educated by cognitive neuroscience and computer simulations, Chalmers' hard problem will evaporate. The hypothetical concept of qualia, pure mental experience, detached from any information-processing role, will be viewed as a peculiar idea of the prescientific era, much like
vitalism
Vitalism is a belief that starts from the premise that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things." Wher ...
... ust as science dispatched vitalismthe science of consciousness will keep eating away at the hard problem of consciousness until it vanishes.
The meta-problem
In 2018, Chalmers highlighted what he calls the "meta-problem of consciousness", another problem related to the hard problem of consciousness:
The meta-problem of consciousness is (to a first approximation) the problem of explaining why we think that there is a ardproblem of consciousness.
In his "second approximation", he says it is the problem of explaining the behavior of "
phenomenal
A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...
reports", and the behavior of expressing a belief that there is a hard problem of consciousness.
Explaining its significance, he says:
Although the meta-problem is strictly speaking an easy problem, it is deeply connected to the hard problem. We can reasonably hope that a solution to the meta-problem will shed significant light on the hard problem. A particularly strong line holds that a solution to the meta-problem will solve or dissolve the hard problem. A weaker line holds that it will not remove the hard problem, but it will constrain the form of a solution.
In other words, the 'strong line' holds that the solution to the meta-problem would provide an explanation of our beliefs about consciousness that is independent of consciousness. That would debunk our beliefs about consciousness, in the same way that explaining beliefs about god in evolutionary terms may provide arguments against theism itself.
In popular culture
British playwright
Sir Tom Stoppard
Sir Tom Stoppard (born , 3 July 1937) is a Czech born British playwright and screenwriter. He has written for film, radio, stage, and television, finding prominence with plays. His work covers the themes of human rights, censorship, and politic ...
's play ''
The Hard Problem
''The Hard Problem'' is a play by British playwright Sir Tom Stoppard, first produced in 2015. The title refers to the hard problem of consciousness, which Stoppard defines as having "subjective First Person experiences"; he notes the strangen ...
'', first produced in 2015, is named after the hard problem of consciousness, which Stoppard defines as having "subjective First Person experiences".
See also
*
Animal consciousness
Animal consciousness, or animal awareness, is the quality or state of self-awareness within a non-human animal, or of being aware of an external object or something within itself. In humans, consciousness has been defined as: sentience, aware ...
*
Artificial consciousness
Artificial consciousness (AC), also known as machine consciousness (MC) or synthetic consciousness (; ), is a field related to artificial intelligence and cognitive robotics. The aim of the theory of artificial consciousness is to "Define that wh ...
*
Blindsight
Blindsight is the ability of people who are cortically blind to respond to visual stimuli that they do not consciously see due to lesions in the primary visual cortex, also known as the striate cortex or Brodmann Area 17. The term was coined by L ...
Cogito, ergo sum
The Latin , usually translated into English as "I think, therefore I am", is the "first principle" of René Descartes's philosophy. He originally published it in French as , in his 1637 ''Discourse on the Method'', so as to reach a wider audie ...
Free will
Free will is the capacity of agents to choose between different possible courses of action unimpeded.
Free will is closely linked to the concepts of moral responsibility, praise, culpability, sin, and other judgements which apply only to actio ...
*
Ideasthesia
Ideasthesia (alternative spelling ideaesthesia) is a neuropsychological phenomenon in which activations of concepts (inducers) evoke perception-like sensory experiences (concurrents). The name comes from the Ancient Greek () and (), meaning 'se ...
*
Information-theoretic death
Information-theoretic death is a term of art used in cryonics to define death in a way that is permanent and independent of any future medical advances, no matter how distant or improbable that may be. Because detailed reading or restoration of in ...
*
Introspection
Introspection is the examination of one's own conscious thoughts and feelings. In psychology, the process of introspection relies on the observation of one's mental state, while in a spiritual context it may refer to the examination of one's s ...
*
Knowledge by acquaintance
In philosophy, a distinction is often made between two different kinds of knowledge: knowledge by acquaintance and knowledge by description. Whereas knowledge by description is something like ordinary propositional knowledge (e.g. "I know that ...
*
List of unsolved problems in biology
This article lists notable unsolved problems in biology.
General biology
Evolution and origins of life
*Origin of life. Exactly how, where, and when did life on Earth originate? Which, if any, of the many hypotheses is correct? What were the ...
*
Mind–body problem
The mind–body problem is a philosophical debate concerning the relationship between thought and consciousness in the human mind, and the brain as part of the physical body. The debate goes beyond addressing the mere question of how mind and bo ...
*
Phenomenalism
In metaphysics, phenomenalism is the view that physical objects cannot justifiably be said to exist in themselves, but only as perceptual phenomena or sensory stimuli (e.g. redness, hardness, softness, sweetness, etc.) situated in time and in ...
*
Philosophy of self
The philosophy of self is the study of wisdom as self at a conceptual level. Many different ideas on what constitutes self have been proposed, including the self being an activity, the self being independent of the senses, the bundle theory of th ...
*
Problem of mental causation
The problem of mental causation is a conceptual issue in the philosophy of mind. That problem, in short, is how to account for the common-sense idea that intentional thoughts or intentional mental states are causes of intentional actions. The prob ...
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Problem of other minds
The problem of other minds is a philosophical problem traditionally stated as the following epistemological question: Given that I can only observe the behavior of others, how can I know that others have minds? The problem is that knowledge of ...