In philosophy, emergentism is the belief in emergence, particularly as it involves consciousness and the philosophy of mind, and as it contrasts with and also does not contrast with reductionism. A property of a system
is said to be emergent if it is a new outcome of some other properties
of the system and their interaction, while it is itself different from
them.
Emergent properties, laws and principles, appear when a system is
studied at a higher level of organization (holistic instead of atomic
level). They often show a high level of complexity, despite the
fundamental principles that regulate the components of the system being
simple. For example, in emergentism, the laws of chemistry are believed
to emerge only from a few fundamental laws of physics (some still not
discovered), biology from chemistry, and psychology from biology,
although we still have not been able to fully deduce these holistic
relations from the atomic level because of their complexity.
Consciousness is believed to appear in certain large neural networks,
but is not an attribute of a single neuron. In emergentism, no mystic
principles are believed to be added at higher level, but emergentism is
naturalistic.
Emergent properties are not identical with, reducible to, or deducible
from the other properties. The different ways in which this
independence requirement can be satisfied lead to variant types of
emergence.
Forms
All varieties of emergentism strive to be compatible with physicalism,
the theory that the universe is composed exclusively of physical
entities, and in particular with the evidence relating changes in the
brain with changes in mental functioning. Many forms of emergentism,
including proponents of complex adaptive systems, do not hold a material
but rather a relational or processual view of the universe.
Furthermore, they view mind–body dualism
as a conceptual error insofar as mind and body are merely different
types of relationships. As a theory of mind (which it is not always),
emergentism differs from idealism, eliminative materialism, identity theories, neutral monism, panpsychism, and substance dualism, whilst being closely associated with property dualism. It is generally not obvious whether an emergent theory of mind embraces mental causation or must be considered epiphenomenal.
Some varieties of emergentism are not specifically concerned with the mind–body problem but constitute a theory of the nature of the universe comparable to pantheism. They suggest a hierarchical or layered view of the whole of nature, with the layers arranged in terms of increasing complexity with each requiring its own special science. Typically physics (mathematical physics, particle physics, and classical physics) is basic, with chemistry built on top of it, then biology, psychology, and social sciences.
Reductionists respond that the arrangement of the sciences is a matter
of convenience, and that chemistry is derivable from physics (and so
forth) in principle, an argument which gained force after the establishment of a quantum-mechanical basis for chemistry.
Other varieties see mind or consciousness as specifically and anomalously requiring emergentist explanation, and therefore constitute a family of positions in the philosophy of mind. Douglas Hofstadter summarises this view as "the soul is more than the sum of its parts". A number of philosophers have offered the argument that qualia constitute the hard problem of consciousness,
and resist reductive explanation in a way that all other phenomena do
not. In contrast, reductionists generally see the task of accounting for
the possibly atypical properties of mind and of living things as a
matter of showing that, contrary to appearances, such properties are
indeed fully accountable in terms of the properties of the basic
constituents of nature and therefore in no way genuinely atypical.
Intermediate positions are possible: for instance, some
emergentists hold that emergence is neither universal nor restricted to
consciousness, but applies to (for instance) living creatures, or self-organising systems, or complex systems.
Some philosophers hold that emergent properties causally interact with more fundamental levels, an idea known as downward causation. Others maintain that higher-order properties simply supervene over lower levels without direct causal interaction.
All the cases so far discussed have been synchronic, i.e. the emergent property exists simultaneously with its basis.
Yet another variation operates diachronically. Emergentists of this type believe that genuinely novel properties can come into being, without being accountable in terms of the preceding history of the universe. (Contrast with indeterminism where it is only the arrangement or configuration of matter that is unaccountable). These evolution-inspired theories often have a theological aspect, as in the process philosophy of Alfred North Whitehead and Charles Hartshorne.
Relationship to vitalism
A refinement of vitalism
may be recognized in contemporary molecular histology in the proposal
that some key organising and structuring features of organisms, perhaps
including even life itself, are examples of emergent processes;
those in which a complexity arises, out of interacting chemical
processes forming interconnected feedback cycles, that cannot fully be
described in terms of those processes since the system as a whole has
properties that the constituent reactions lack.
Whether emergent system properties should be grouped with traditional vitalist concepts is a matter of semantic controversy.
In a light-hearted millennial vein, Kirshner and Michison call research
into integrated cell and organismal physiology “molecular vitalism.”
According to Emmeche et al. (1997):
"On the one hand, many scientists and philosophers regard emergence
as having only a pseudo-scientific status. On the other hand, new
developments in physics, biology, psychology, and crossdisciplinary
fields such as cognitive science, artificial life, and the study of
non-linear dynamical systems have focused strongly on the high level
'collective behaviour' of complex systems, which is often said to be
truly emergent, and the term is increasingly used to characterize such
systems."
Emmeche et al. (1998) state that "there is a very important
difference between the vitalists and the emergentists: the vitalist's
creative forces were relevant only in organic substances, not in
inorganic matter. Emergence hence is creation of new properties
regardless of the substance involved." "The assumption of an
extra-physical vitalis (vital force, entelechy, élan vital,
etc.), as formulated in most forms (old or new) of vitalism, is usually
without any genuine explanatory power. It has served altogether too
often as an intellectual tranquilizer or verbal sedative—stifling scientific inquiry rather than encouraging it to proceed in new directions."
In The Conscious Mind (1996) David Chalmers argues that comparisons between vitalism and the "hard problem of consciousness" commit a category error,
because, unlike life, consciousness is irreducible to lower-order
physical facts. It is logically impossible that one could perfectly
replicate all the lower order facts of, say, wombat cellular biology without the higher order facts about the wombat coming along for the ride. In contrast, it is logically possible that one all the physical facts of the world could be the same without consciousness ever coming into the question (i.e. philosophical zombies).
By Chalmers account, facts about consciousness are "further facts about
the world in addition to the physical facts." Chalmers concludes that
consciousness is a fundamental fact of nature, and thus has no need to
emerge out of anything.
History
John Stuart Mill
John Stuart Mill outlined his version of emergentism in System of Logic (1843). Mill argued that the properties of some physical systems, such as those in which dynamic forces combine to produce simple motions, are subject to a law of nature he called the "Composition of Causes".
According to Mill, emergent properties are not subject to this law, but
instead amount to more than the sums of the properties of their parts.
Mill believed that various chemical reactions (poorly understood in his time) could provide examples of emergent properties, although some critics believe that modern physical chemistry has shown that these reactions can be given satisfactory reductionist explanations. For instance, it has been claimed by Dirac that the whole of chemistry is, in principle,
contained in the Schrödinger equation.
Put in abstract terms the emergent theory asserts that there are certain wholes, composed (say)
of constituents A, B, and C in a relation R to each other; that all wholes composed of
constituents of the same kind as A, B, and C in relations of the same kind as R have certain
characteristic properties; that A, B, and C are capable of occurring in other kinds of complex
where the relation is not of the same kind as R; and that the characteristic properties of the
whole R(A, B, C) cannot, even in theory, be deduced from the most complete knowledge of
the properties of A, B, and C in isolation or in other wholes which are not of the form R(A, B,
C).
This definition amounted to the claim that mental properties would count as emergent if and only if philosophical zombies were metaphysically possible. Many philosophers take this position to be inconsistent with some formulations of psychophysicalsupervenience.
C. Lloyd Morgan and Samuel Alexander
Samuel Alexander's views on emergentism, argued in Space, Time, and Deity (1920), were inspired in part by the ideas in psychologist C. Lloyd Morgan's Emergent Evolution. Alexander believed that emergence was fundamentally inexplicable, and that emergentism was simply a "brute empirical fact":
"The higher quality emerges from the lower level of existence and
has its roots therein, but it emerges therefrom, and it does not belong
to that level, but constitutes its possessor a new order of existent
with its special laws of behaviour. The existence of emergent qualities
thus described is something to be noted, as some would say, under the
compulsion of brute empirical fact, or, as I should prefer to say in
less harsh terms, to be accepted with the “natural piety” of the
investigator. It admits no explanation." (Space, Time, and Deity)
Despite the causal and explanatory gap between the phenomena on different levels, Alexander held that emergent qualities were notepiphenomenal. His view can perhaps best be described as a form of non-reductive physicalism (NRP) or supervenience theory.
Emergentism strives to be compatible with physicalism, and
physicalism, according to Kim, has a principle of causal closure
according to which every physical event is fully accountable in terms of
physical causes. This seems to leave no "room"
for mental causation to operate. If our bodily movements were caused by the preceding state of our bodies and our decisions and intentions, they would be overdetermined. Mental causation in this sense is not
the same as free will,
but is only the claim that mental states are causally relevant. If
emergentists respond by abandoning the idea of mental causation, their
position becomes a form of epiphenomenalism.
In detail: he proposes (using the chart on the right) that M1 causes M2 (these are mental events) and P1 causes P2 (these are physical events). P1 realises M1 and P2 realises M2. However M1 does not causally effect P1 (i.e., M1 is a consequent event of P1). If P1 causes P2, and M1 is a result of P1, then M2 is a result of P2. He says that the only alternatives to this problem is to accept dualism (where the mental events are independent of the physical events) or eliminativism (where the mental events do not exist).
There is neither an academic nor an international legal consensus regarding the proper definition of the word "terrorism". Some scholars believe the actions of governments can be labelled "terrorism". Using the term 'terrorism' to mean violent action used with the predominant intention of causing terror, Paul James and Jonathan Friedman distinguish between state terrorism against non-combatants and state terrorism against combatants, including 'shock and awe' tactics:
Shock and Awe" as a subcategory of "rapid dominance" is
the name given to massive intervention designed to strike terror into
the minds of the enemy. It is a form of state-terrorism. The concept was
however developed long before the Second Gulf War by Harlan Ullman as
chair of a forum of retired military personnel.
However, others, including governments, international organisations,
private institutions and scholars, believe the term "terrorism" is
applicable only to the actions of violent non-state actors.
Historically, the term terrorism was used to refer to actions taken by
governments against their own citizens whereas now it is more often
perceived as targeting of non-combatants as part of a strategy directed against governments.
Historian Henry Commager wrote that "Even when definitions of terrorism allow for state terrorism, state actions in this area tend to be seen through the prism of war or national self-defense, not terror." While states may accuse other states of state-sponsored terrorism
when they support insurgencies, individuals who accuse their
governments of terrorism are seen as radicals, because actions by
legitimate governments are not generally seen as illegitimate. Academic
writing tends to follow the definitions accepted by states. Most states use the term "terrorism" for non-state actors only.
The Encyclopædia Britannica Online
defines terrorism generally as "the systematic use of violence to
create a general climate of fear in a population and thereby to bring
about a particular political objective", and states that "terrorism is
not legally defined in all jurisdictions." The encyclopedia adds that
"[e]stablishment terrorism, often called state or state-sponsored
terrorism, is employed by governments—or more often by factions within
governments—against that government's citizens, against factions within
the government, or against foreign governments or groups."
While the most common modern usage of the word terrorism refers to civilian-victimising political violence by insurgents or conspirators,
several scholars make a broader interpretation of the nature of
terrorism that encompasses the concepts of state terrorism and
state-sponsored terrorism. Michael Stohl
argues, "The use of terror tactics is common in international relations
and the state has been and remains a more likely employer of terrorism
within the international system than insurgents.
Stohl clarifies, however, that "[n]ot all acts of state violence are
terrorism. It is important to understand that in terrorism the violence
threatened or perpetrated, has purposes broader than simple physical
harm to a victim. The audience of the act or threat of violence is more
important than the immediate victim."
Scholar Gus Martin
describes state terrorism as terrorism "committed by governments and
quasi-governmental agencies and personnel against perceived threats",
which can be directed against both domestic and foreign targets. Noam Chomsky defines state terrorism as "terrorism practised by states (or governments) and their agents and allies".
Stohl and George A. Lopez
have designated three categories of state terrorism, based on the
openness/secrecy with which the alleged terrorist acts are performed,
and whether states directly perform the acts, support them, or acquiesce
in them.
History
The Drownings at Nantes were a series of mass executions by drowning during the Reign of Terror in France
Aristotle wrote critically of terror employed by tyrants against their subjects. The earliest use of the word terrorism identified by the Oxford English Dictionary is a 1795 reference to tyrannical state behavior, the "reign of terrorism" in France. In that same year, Edmund Burke decried the "thousands of those hell-hounds called terrorists" who he believed threatened Europe. During the Reign of Terror, the Jacobin government and other factions of the French Revolution
used the apparatus of the state to kill and intimidate political
opponents, and the Oxford English Dictionary includes as one definition
of terrorism "Government by intimidation carried out by the party in
power in France between 1789–1794".
The original general meaning of terrorism was of terrorism by the
state, as reflected in the 1798 supplement of the Dictionnaire of the Académie française, which described terrorism as systeme, regime de la terreur. Myra Williamson wrote:
The meaning of "terrorism" has undergone a
transformation. During the Reign of Terror, a regime or system of
terrorism was used as an instrument of governance, wielded by a recently
established revolutionary state against the enemies of the people. Now the term "terrorism" is commonly used to describe terrorist acts committed by non-state or sub-national entities against a state. (italics in original)
Later examples of state terrorism include the police state measures employed by the Soviet Union beginning in the 1930s, and by Germany's Nazi regime in the 1930s and 1940s.
According to Igor Primoratz, "Both [the Nazis and the Soviets] sought
to impose total political control on society. Such a radical aim could
be pursued only by a similarly radical method: by terrorism directed by
an extremely powerful political police at an atomized and defenseless
population. Its success was due largely to its arbitrary character—to
the unpredictability of its choice of victims. In both countries, the
regime first suppressed all opposition; when it no longer had any
opposition to speak of, political police took to persecuting 'potential'
and 'objective opponents'. In the Soviet Union, it was eventually
unleashed on victims chosen at random."
The terror of tsarism was directed against the proletariat. Our Extraordinary Commissions shoot landlords, capitalists, and generals who are striving to restore the capitalist order. Do you grasp this... distinction? Yes? For us communists it is quite sufficient.
Military actions primarily directed against non-combatant targets
have also been referred to as state terrorism. For example, the bombing of Guernica has been called an act of terrorism. Other examples of state terrorism may include the World War II bombings of Pearl Harbor, London, Dresden, Chongqing, and Hiroshima.
An act of sabotage, sometimes regarded as an act of terrorism, was the peacetime sinking of the Rainbow Warrior, a ship owned by Greenpeace, which occurred while in port at Auckland, New Zealand on July 10, 1985. The bomb detonation killed Fernando Pereira, a Dutch photographer. The organisation who committed the attack, the DGSE, is a branch of France's intelligence services. The agents responsible pleaded guilty to manslaughter
as part of a plea deal and were sentenced to ten years in prison, but
were secretly released early to France under an agreement between the
two countries' governments.
Another example is the British Military Reaction Force
in Northern Ireland during the 1970s, which murdered innocent civilians
from the Catholic community in order to stir up ethnic hatred and "take
the heat off the army".
In November 2013, a BBC Panorama documentary was aired about the
MRF. It drew on information from seven former members, as well as a
number of other sources. Soldier H said: "We operated initially with
them thinking that we were the UVF." Soldier F added: "We wanted to cause confusion." In June 1972, he was succeeded as commander by Captain James 'Hamish' McGregor.
In June 2014, in the wake of the Panorama programme, the Police Service of Northern Ireland (PSNI) opened an investigation into the matter.
In an earlier review of the programme, the position of the PSNI was
that none of the statements by soldiers in the programme could be taken
as an admission of criminality.
By country
China
The Uyghur American Association has claimed that Beijing's military approach to terrorism in Xinjiang is state terrorism. The Chinese state has also been accused of state terrorism in Tibet.
France
The sinking of the Rainbow Warrior took place in New Zealand's Auckland Harbour on July 10, 1985. It was an attack carried out by French DGSE agents Captain Dominique Prieur and Commander Alain Mafart aimed at sinking the flagship craft of the Greenpeace Organisation in order to stop her from interfering in French nuclear testing in the South Pacific. The attack resulted in the death of Greenpeace photographer Fernando Pereira and led to a huge uproar over the first ever attack on New Zealand's sovereignty. France initially denied any involvement in the attack, and it even joined in condemning the attack as a terrorist act. In July 1986, a United Nations-sponsored
mediation effort between New Zealand and France resulted in the
transfer of the two prisoners to the French Polynesian island of Hao, so they could serve three years there, as well as an apology and a NZD 13 million payment from France to New Zealand.
In the 1980s, Libya under Muammar Gaddafi was accused of state terrorism following attacks abroad such as the Lockerbie bombing. Between 9 July and 15 August 1984 seventeen merchant vessels were damaged in the Gulf of Suez and Bab al-Mandeb straits by underwater explosions. Terrorist group Al Jihad (thought to be a pro-IranianShiite group connected to the Palestine Liberation Organisation) issued a claim of responsibility for the mining, but circumstantial evidence indicated that Libya was responsible.
The British state has been accused of involvement in state terrorism in the Northern Ireland conflict from the 1960s to 1990s by covertly assisting the loyalist paramilitaries.
Argentines commemorate the victims of the U.S.-backed military junta on 24 March 2019
Ruth J Blakeley, Professor of Politics and International Relations at the University of Sheffield, accuses the United States
of sponsoring and deploying state terrorism, which she defines as "the
illegal targeting of individuals that the state has a duty to protect in
order to instill fear in a target audience beyond the direct victim",
on an "enormous scale" during the Cold War. The United States government justified this policy by saying it needed to contain the spread of Communism,
but Blakeley says the United States government also used it as a means
to buttress and promote the interests of U.S. elites and multinational
corporations. The U.S. supported governments who employed death squads throughout Latin America and counterinsurgency training of right-wing military forces included advocating the interrogation and torture of suspected insurgents. J. Patrice McSherry, a professor of political science at Long Island University, says "hundreds of thousands of Latin Americans
were tortured, abducted or killed by right-wing military regimes as
part of the U.S.-led anti-communist crusade," which included U.S.
support for Operation Condor and the Guatemalan military during the Guatemalan Civil War. More people were repressed and killed throughout Latin America in the last three decades of the Cold War than in the Soviet Union and the Eastern Bloc, according to historian John Henry Coatsworth.
Declassified documents from the U.S. Embassy in Jakarta in 2017 confirm that the U.S. directly facilitated and encouraged the mass murder of hundreds of thousands of suspected Communists in Indonesia during the mid-1960s. Bradley Simpson, Director of the Indonesia/East Timor Documentation Project at the National Security Archive,
says "Washington did everything in its power to encourage and
facilitate the army-led massacre of alleged PKI members, and U.S.
officials worried only that the killing of the party's unarmed
supporters might not go far enough, permitting Sukarno to return to
power and frustrate the [Johnson] Administration's emerging plans for a
post-Sukarno Indonesia." According to Simpson, the terror in Indonesia was an "essential building block of the quasi neo-liberal policies the West would attempt to impose on Indonesia in the years to come".
Historian John Roosa, who commented on documents which were released by
the U.S. embassy in Jakarta in 2017, said they confirmed that "the U.S.
was part and parcel of the operation, strategizing with the Indonesian
army and encouraging them to go after the PKI."
Geoffrey B. Robinson, a historian at UCLA, argues that without the
support of the U.S. and other powerful Western states, the Indonesian
Army's program of mass killings would not have happened.
The
chairman of the United Nations Counter-Terrorism Committee has said the
twelve previous international conventions on terrorism had never
referred to state terrorism, which was not an international legal
concept, and when states abuse their powers they should be judged
against international conventions which deal with war crimes, international human rights law, and international humanitarian law, rather than international anti-terrorism statutes. In a similar vein, Kofi Annan, at the time the United Nations Secretary-General, said it is "time to set aside debates on so-called 'state terrorism'. The use of force by states is already regulated under international law". Annan added, "...regardless
of the differences between governments on the question of the
definition of terrorism, what is clear and what we can all agree on is
any deliberate attack on innocent civilians [or non-combatants],
regardless of one's cause, is unacceptable and fits into the definition
of terrorism."
Dr. Bruce Hoffman has argued that failing to differentiate between state and non-state violence
ignores the fact that there is a "fundamental qualitative difference
between the two types of violence." Hoffman argues that even in war,
there are rules and accepted norms of behaviour that prohibit certain
types of weapons and tactics and outlaw attacks on specific categories
of targets. For instance, rules which are codified in the Geneva and Hague Conventions on warfare prohibit taking civilians as hostages, outlaw reprisals against either civilians or POWs, recognise neutral territory,
etc. Hoffman says "even the most cursory review of terrorist tactics
and targets over the past quarter century reveals that terrorists have
violated all these rules." Hoffman also says that when states transgress
these rules of war "the term "war crime" is used to describe such acts."
Walter Laqueur
has said those who argue that state terrorism should be included in
studies of terrorism ignore the fact that "The very existence of a state is based on its monopoly of power.
If it were different, states would not have the right, nor would they
be in a position, to maintain that minimum of order on which all
civilized life rests." Calling the concept a "red herring"
he stated: "This argument has been used by the terrorists themselves,
arguing that there is no difference between their activities and those
by governments and states. It has also been employed by some
sympathizers, and it rests on the deliberate obfuscation between all
kinds of violence..."
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 substance" view of the nature of reality as opposed to a "two-substance" (dualism) or "many-substance" (pluralism) view. Both the definition of "physical" and the meaning of physicalism have been debated.
Physicalism is closely related to materialism. Physicalism grew out of materialism with advancements of the physical sciences
in explaining observed phenomena. The terms are often used
interchangeably, although they are sometimes distinguished, for example
on the basis of physics describing more than just matter (including
energy and physical law).
According to a 2009 survey, physicalism is the majority view among philosophers, but there remains significant opposition to physicalism. Neuroplasticity is one such evidence that is used in support of a non-physicalist view. The philosophical zombie argument is another attempt to challenge physicalism.
Definition of physicalism
The word "physicalism" was introduced into philosophy in the 1930s by Otto Neurath and Rudolf Carnap.
The use of "physical" in physicalism is a philosophical concept
and can be distinguished from alternative definitions found in the
literature (e.g. Karl Popper defined a physical proposition to be one which can at least in theory be denied by observation).
A "physical property", in this context, may be a metaphysical or
logical combination of properties which are physical in the ordinary
sense. It is common to express the notion of "metaphysical or logical
combination of properties" using the notion of supervenience: A property A is said to supervene on a property B if any change in A necessarily implies a change in B.
Since any change in a combination of properties must consist of a
change in at least one component property, we see that the combination
does indeed supervene on the individual properties. The point of this
extension is that physicalists usually suppose the existence of various
abstract concepts which are non-physical in the ordinary sense of the
word; so physicalism cannot be defined in a way that denies the
existence of these abstractions. Also, physicalism defined in terms of
supervenience does not entail that all properties in the actual world
are type identical to physical properties. It is, therefore, compatible with multiple realizability.
From the notion of supervenience, we see that, assuming that
mental, social, and biological properties supervene on physical
properties, it follows that two hypothetical worlds cannot be identical
in their physical properties but differ in their mental, social or
biological properties.
Two common approaches to defining "physicalism" are the
theory-based and object-based approaches. The theory-based conception of
physicalism proposes that "a property is physical if and only if it
either is the sort of property that physical theory tells us about or
else is a property which metaphysically (or logically) supervenes on the
sort of property that physical theory tells us about".
Likewise, the object-based conception claims that "a property is
physical if and only if: it either is the sort of property required by a
complete account of the intrinsic nature of paradigmatic physical
objects and their constituents or else is a property which
metaphysically (or logically) supervenes on the sort of property
required by a complete account of the intrinsic nature of paradigmatic
physical objects and their constituents".
Physicalists have traditionally opted for a "theory-based" characterization of the physical either in terms of current physics, or a future (ideal) physics. These two theory-based conceptions of the physical represent both horns of Hempel's dilemma (named after the late philosopher of science and logical empiricist Carl Gustav Hempel):
an argument against theory-based understandings of the physical. Very
roughly, Hempel's dilemma is that if we define the physical by reference
to current physics, then physicalism is very likely to be false, as it
is very likely (by pessimistic meta-induction)
that much of current physics is false. But if we instead define the
physical in terms of a future (ideal) or completed physics, then
physicalism is hopelessly vague or indeterminate.
While the force of Hempel's dilemma against theory-based conceptions of the physical remains contested, alternative "non-theory-based" conceptions of the physical have also been proposed. Frank Jackson (1998) for example, has argued in favour of the aforementioned "object-based" conception of the physical. An objection to this proposal, which Jackson himself noted in 1998, is that if it turns out that panpsychism or panprotopsychism
is true, then such a non-materialist understanding of the physical
gives the counterintuitive result that physicalism is, nevertheless,
also true since such properties will figure in a complete account of
paradigmatic examples of the physical.
David Papineau and Barbara Montero have advanced and subsequently defended
a "via negativa" characterization of the physical. The gist of the via
negativa strategy is to understand the physical in terms of what it is
not: the mental. In other words, the via negativa strategy understands
the physical as "the non-mental". An objection to the via negativa
conception of the physical is that (like the object-based conception) it
doesn't have the resources to distinguish neutral monism (or panprotopsychism) from physicalism.
Further, Restrepo (2012) argues that this conception of the physical
makes core non-physical entities of non-´physicalist metaphysics, like
God, Cartesian souls and abstract numbers, physical and thus either
false or trivially true: "God is non-mentally-and-non-biologically
identifiable as the thing that created the universe. Sup- posing
emergentism is true, non-physical emergent properties are
non-mentally-and-non-biologically identifiable as non-linear effects of
certain arrangements of matter. The immaterial Cartesian soul is
non-mentally-and-non-biologically identifiable as one of the things that
interact causally with certain particles (coincident with the pineal
gland). The Platonic number eight is non-mentally-and-non-biologically
identifiable as the number of planets orbiting the Sun".
Supervenience-based definitions of physicalism
Adopting a supervenience-based account of the physical, the definition of physicalism as "all properties are physical" can be unraveled to:
1) Physicalism is true at a possible world w if and only if any world that is a physical duplicate of w is also a duplicate of w simpliciter.
Applied to the actual world (our world), statement 1 above is the
claim that physicalism is true at the actual world if and only if at every possible world
in which the physical properties and laws of the actual world are
instantiated, the non-physical (in the ordinary sense of the word)
properties of the actual world are instantiated as well. To borrow a
metaphor from Saul Kripke
(1972), the truth of physicalism at the actual world entails that once
God has instantiated or "fixed" the physical properties and laws of our
world, then God's work is done; the rest comes "automatically".
Unfortunately, statement 1 fails to capture even a necessary condition for physicalism to be true at a world w. To see this, imagine a world in which there are only
physical properties—if physicalism is true at any world it is true at
this one. But one can conceive physical duplicates of such a world that
are not also duplicates simpliciter of it: worlds that have the
same physical properties as our imagined one, but with some additional
property or properties. A world might contain "epiphenomenal ectoplasm",
some additional pure experience that does not interact with the
physical components of the world and is not necessitated by them (does
not supervene on them). To handle the epiphenomenal ectoplasm problem, statement 1 can be modified to include a "that's-all" or "totality" clause or be restricted to "positive" properties. Adopting the former suggestion here, we can reformulate statement 1 as follows:
2) Physicalism is true at a possible world w if and only if any world that is a minimal physical duplicate of w is a duplicate of w simpliciter.
Applied in the same way, statement 2 is the claim that physicalism is true at a possible world w if and only if any world that is a physical duplicate of w (without any further changes), is duplicate of w
without qualification. This allows a world in which there are only
physical properties to be counted as one at which physicalism is true,
since worlds in which there is some extra stuff are not "minimal"
physical duplicates of such a world, nor are they minimal physical
duplicates of worlds that contain some non-physical properties that are
metaphysically necessitated by the physical.
But while statement 2 overcomes the problem of worlds at which
there is some extra stuff (sometimes referred to as the "epiphenomenal
ectoplasm problem") it faces a different challenge: the so-called "blockers problem". Imagine a world where the relation between the physical and non-physical properties at this world (call the world w1)
is slightly weaker than metaphysical necessitation, such that a certain
kind of non-physical intervener—"a blocker"—could, were it to exist at w1, prevent the non-physical properties in w1 from being instantiated by the instantiation of the physical properties at w1. Since statement 2 rules out worlds which are physical duplicates of w1
that also contain non-physical interveners by virtue of the minimality,
or that's-all clause, statement 2 gives the (allegedly) incorrect
result that physicalism is true at w1. One response to
this problem is to abandon statement 2 in favour of the alternative
possibility mentioned earlier in which supervenience-based formulations
of physicalism are restricted to what David Chalmers
(1996) calls "positive properties". A positive property is one that
"...if instantiated in a world W, is also instantiated by the
corresponding individual in all worlds that contain W as a proper part." Following this suggestion, we can then formulate physicalism as follows:
3) Physicalism is true at a possible world w if and only if any world that is a physical duplicate of w is a positive duplicate of w.
On the face of it, statement 3 seems able to handle both the
epiphenomenal ectoplasm problem and the blockers problem. With regard to
the former, statement 3 gives the correct result that a purely physical
world is one at which physicalism is true, since worlds in which there
is some extra stuff are positive duplicates of a purely physical world.
With regard to the latter, statement 3 appears to have the consequence
that worlds in which there are blockers are worlds where positive
non-physical properties of w1 will be absent, hence w1 will not be counted as a world at which physicalism is true. Daniel Stoljar (2010) objects to this response to the blockers problem on the basis that since the non-physical properties of w1
aren't instantiated at a world in which there is a blocker, they are
not positive properties in Chalmers' (1996) sense, and so statement 3
will count w1 as a world at which physicalism is true after all.
A further problem for supervenience-based formulations of physicalism is the so-called "necessary beings problem".
A necessary being in this context is a non-physical being that exists
in all possible worlds (for example what theists refer to as God).
A necessary being is compatible with all the definitions provided,
because it is supervenient on everything; yet it is usually taken to
contradict the notion that everything is physical. So any
supervenience-based formulation of physicalism will at best state a necessary but not sufficient condition for the truth of physicalism.
Additional objections have been raised to the above definitions
provided for supervenience physicalism: one could imagine an alternate
world that differs only by the presence of a single ammonium molecule
(or physical property), and yet based on statement 1, such a world might
be completely different in terms of its distribution of mental
properties.
Furthermore, there are differences expressed concerning the modal
status of physicalism; whether it is a necessary truth, or is only true
in a world which conforms to certain conditions (i.e. those of
physicalism).
Realisation physicalism
Closely
related to supervenience physicalism, is realisation physicalism, the
thesis that every instantiated property is either physical or realised
by a physical property.
Token physicalism
Token physicalism is the proposition that "for every actual
particular (object, event or process) x, there is some physical
particular y such that x = y". It is intended to capture the idea of
"physical mechanisms". Token physicalism is compatible with property dualism,
in which all substances are "physical", but physical objects may have
mental properties as well as physical properties. Token physicalism is
not however equivalent to supervenience physicalism. Firstly, token
physicalism does not imply supervenience physicalism because the former
does not rule out the possibility of non-supervenient properties
(provided that they are associated only with physical particulars).
Secondarily, supervenience physicalism does not imply token physicalism,
for the former allows supervenient objects (such as a "nation", or
"soul") that are not equal to any physical object.
Reductionism and emergentism
Reductionism
There are multiple versions of reductionism.
In the context of physicalism, the reductions referred to are of a
"linguistic" nature, allowing discussions of, say, mental phenomena to
be translated into discussions of physics. In one formulation, every
concept is analysed in terms of a physical concept. One counter-argument
to this supposes there may be an additional class of expressions which
is non-physical but which increases the expressive power of a theory.
Another version of reductionism is based on the requirement that one
theory (mental or physical) be logically derivable from a second.
The combination of reductionism and physicalism is usually called
reductive physicalism in the philosophy of mind. The opposite view is
non-reductive physicalism. Reductive physicalism is the view that mental
states are both nothing over and above physical states and reducible to
physical states. One version of reductive physicalism is type physicalism
or mind-body identity theory. Type physicalism asserts that "for every
actually instantiated property F, there is some physical property G such
that F=G". Unlike token physicalism, type physicalism entails supervenience physicalism.
Reductive versions of physicalism are increasingly unpopular as
they do not account for mental lives. The brain on this position as a
physical substance has only physical attributes such as a particular
volume, a particular mass, a particular density, a particular location, a
particular shape, and so on. However, the brain on this position does
not have any mental attributes. The brain is not overjoyed or unhappy.
The brain is not in pain. When a person's back aches and he or she is in
pain, it is not the brain that is suffering even though the brain is
associated with the neural circuitry that provides the experience of
pain. Reductive physicalism therefore cannot explain mental lives. In
the event of fear, for example, doubtlessly there is neural activity
that is corresponding with the experience of fear. However, the brain
itself is not fearful. Fear cannot be reduced to a physical brain state
even though it is corresponding with neural activity in the brain. For
this reason, reductive physicalism is argued to be indefensible as it
cannot be reconciled with mental experience.
Another common argument against type physicalism is multiple realizability,
the possibility that a psychological process (say) could be
instantiated by many different neurological processes (even
non-neurological processes, in the case of machine or alien
intelligence).
For in this case, the neurological terms translating a psychological
term must be disjunctions over the possible instantiations, and it is
argued that no physical law can use these disjunctions as terms.
Type physicalism was the original target of the multiple realizability
argument, and it is not clear that token physicalism is susceptible to
objections from multiple realizability.
Emergentism
There are two versions of emergentism, the strong version and the
weak version. Supervenience physicalism has been seen as a strong
version of emergentism, in which the subject's psychological experience
is considered genuinely novel.
Non-reductive physicalism, on the other side, is a weak version of
emergentism because it does not need that the subject's psychological
experience be novel. The strong version of emergentism is incompatible
with physicalism. Since there are novel mental states, mental states are
not nothing over and above physical states. However, the weak version
of emergentism is compatible with physicalism.
We can see that emergentism is actually a very broad view. Some
forms of emergentism appear either incompatible with physicalism or
equivalent to it (e.g. posteriori physicalism), others appear to merge both dualism
and supervenience. Emergentism compatible with dualism claims that
mental states and physical states are metaphysically distinct while
maintaining the supervenience of mental states on physical states. This
proposition however contradicts supervenience physicalism, which asserts
a denial of dualism.
A priori versus a posteriori physicalism
Physicalists
hold that physicalism is true. A natural question for physicalists,
then, is whether the truth of physicalism is deducible a priori
from the nature of the physical world (i.e., the inference is justified
independently of experience, even though the nature of the physical
world can itself only be determined through experience) or can only be
deduced a posteriori
(i.e., the justification of the inference itself is dependent upon
experience). So-called "a priori physicalists" hold that from knowledge
of the conjunction
of all physical truths, a totality or that's-all truth (to rule out
non-physical epiphenomena, and enforce the closure of the physical
world), and some primitive indexical truths such as "I am A" and "now is B", the truth of physicalism is knowable a priori.
Let "P" stand for the conjunction of all physical truths and laws, "T"
for a that's-all truth, "I" for the indexical "centering" truths, and
"N" for any [presumably non-physical] truth at the actual world. We can
then, using the material conditional "→", represent a priori physicalism as the thesis that PTI → N is knowable a priori. An important wrinkle here is that the concepts
in N must be possessed non-deferentially in order for PTI → N to be
knowable a priori. The suggestion, then, is that possession of the
concepts in the consequent, plus the empirical information in the antecedent is sufficient for the consequent to be knowable a priori.
An "a posteriori physicalist", on the other hand, will reject the
claim that PTI → N is knowable a priori. Rather, they would hold that
the inference from PTI to N is justified by metaphysical considerations
that in turn can be derived from experience. So the claim then is that
"PTI and not N" is metaphysically impossible.
One commonly issued challenge to a priori physicalism and to physicalism in general is the "conceivability argument", or zombie argument. At a rough approximation, the conceivability argument runs as follows:
P1) PTI and not Q (where "Q" stands for the conjunction of
all truths about consciousness, or some "generic" truth about someone
being "phenomenally" conscious [i.e., there is "something it is like" to be a person x] ) is conceivable (i.e., it is not knowable a priori that PTI and not Q is false).
P2) If PTI and not Q is conceivable, then PTI and not Q is metaphysically possible.
P3) If PTI and not Q is metaphysically possible then physicalism is false.
C) Physicalism is false.
Here proposition P3 is a direct application of the
supervenience of consciousness, and hence of any supervenience-based
version of physicalism: If PTI and not Q is possible, there is some possible world
where it is true. This world differs from [the relevant indexing on]
our world, where PTIQ is true. But the other world is a minimal physical
duplicate of our world, because PT is true there. So there is a
possible world which is a minimal physical duplicate of our world, but
not a full duplicate; this contradicts the definition of physicalism
that we saw above.
Since a priori physicalists hold that PTI → N is a priori, they
are committed to denying P1) of the conceivability argument. The a
priori physicalist, then, must argue that PTI and not Q, on ideal
rational reflection, is incoherent or contradictory.
A posteriori physicalists, on the other hand, generally accept
P1) but deny P2)--the move from "conceivability to metaphysical
possibility". Some a posteriori physicalists think that unlike the
possession of most, if not all other empirical
concepts, the possession of consciousness has the special property that
the presence of PTI and the absence of consciousness will be
conceivable—even though, according to them, it is knowable a posteriori
that PTI and not Q is not metaphysically possible. These a posteriori
physicalists endorse some version of what Daniel Stoljar (2005) has
called "the phenomenal concept strategy".
Roughly speaking, the phenomenal concept strategy is a label for those a
posteriori physicalists who attempt to show that it is only the concept of consciousness—not the property—that is in some way "special" or sui generis. Other a posteriori physicalists
eschew the phenomenal concept strategy, and argue that even ordinary
macroscopic truths such as "water covers 60% of the earth's surface" are
not knowable a priori from PTI and a non-deferential grasp of the
concepts "water" and "earth" et cetera. If this is correct, then
we should (arguably) conclude that conceivability does not entail
metaphysical possibility, and P2) of the conceivability argument against
physicalism is false.
Other views
Realistic physicalism
Galen Strawson's realistic physicalism or realistic monism entails panpsychism – or at least micropsychism.
Galen Strawson doesn't take into account procedurality, cause and
effect relationship and the fact that ontological states (how things
are) are not affected by human knowledge or interpretation (except in
human interactions when knowledge plays an active role). Strawson
doesn't take into account the fact that the soul theory is unprocedural
and ontologically nondefinable; because if it were definable but unknown
to humans it could have been described scientifically but humans failed
to complete the task successfully (not being able to access physically
the soul doesn't exclude the creation of a formal theory about it; but
that theory would have to be logical in order to be scientific).
Strawson argues that "many—perhaps most—of those who call themselves
physicalists or materialists [are mistakenly] committed to the thesis
that physical stuff is, in itself, in its fundamental nature, something
wholly and utterly non-experiential... even when they are prepared to
admit with Eddington that physical stuff has, in itself, 'a nature
capable of manifesting itself as mental activity', i.e. as experience or
consciousness". Because experiential phenomena allegedly cannot be emergent from wholly non-experiential phenomena, philosophers are driven to substance dualism, property dualism, eliminative materialism and "all other crazy attempts at wholesale mental-to-non-mental reduction".
Real physicalists must accept that at least some ultimates are intrinsically experience-involving. They must at least embrace micropsychism.
Given that everything concrete is physical, and that everything
physical is constituted out of physical ultimates, and that experience
is part of concrete reality, it seems the only reasonable position, more
than just an 'inference to the best explanation'... Micropsychism is
not yet panpsychism, for as things stand realistic physicalists can
conjecture that only some types of ultimates are intrinsically
experiential. But they must allow that panpsychism may be true, and the
big step has already been taken with micropsychism, the admission that
at least some ultimates must be experiential. 'And were the inmost
essence of things laid open to us' I think that the idea that some but
not all physical ultimates are experiential would look like the idea
that some but not all physical ultimates are spatio-temporal (on the
assumption that spacetime is indeed a fundamental feature of reality). I
would bet a lot against there being such radical heterogeneity at the
very bottom of things. In fact (to disagree with my earlier self) it is
hard to see why this view would not count as a form of dualism... So now
I can say that physicalism, i.e. real physicalism, entails
panexperientialism or panpsychism. All physical stuff is energy, in one
form or another, and all energy, I trow, is an experience-involving
phenomenon. This sounded crazy to me for a long time, but I am quite
used to it, now that I know that there is no alternative short of
'substance dualism'... Real physicalism, realistic physicalism, entails
panpsychism, and whatever problems are raised by this fact are problems a
real physicalist must face.
— Galen Strawson, Consciousness and Its Place in Nature: Does Physicalism Entail Panpsychism?
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, qualia, or sentience.
For example, if a philosophical zombie were poked with a sharp object
it would not inwardly feel any pain, yet it would outwardly behave
exactly as if it did feel pain, including verbally expressing pain.
Relatedly, a zombie world is a hypothetical world indistinguishable from
our world but in which all beings lack conscious experience.
Philosophical zombie arguments are used in support of mind-body dualism against forms of physicalism such as materialism, behaviorism and functionalism. These arguments aim to refute the possibility of any physicalist solution to the "hard problem of consciousness" (the problem of accounting for subjective, intrinsic, first-person, what-it's-like-ness). Proponents of philosophical zombie arguments, such as the philosopher David Chalmers, argue that since a philosophical zombie is by definition physically identical to a conscious person, even its logical possibility would refute physicalism, because it would establish the existence of conscious experience as a further fact. Such arguments have been criticized by many philosophers. Some physicalists like Daniel Dennett argue that philosophical zombies are logically incoherent and thus impossible; other physicalists like Christopher Hill argue that philosophical zombies are coherent but not metaphysically possible.
History
Philosophical zombies are associated with David Chalmers, but it was philosopher Robert Kirk
who first used the term "zombie" in this context in 1974. Prior to
that, Keith Campbell made a similar argument in his 1970 book Body and Mind, using the term "Imitation Man." Chalmers further developed and popularized the idea in his work.
There has been a lively debate about what the zombie argument shows. Critics who primarily argue that zombies are not conceivable include Daniel Dennett, Nigil J. T. Thomas, David Braddon-Mitchell, and Robert Kirk; critics who assert mostly that conceivability does not entail possibility include Katalin Balog, Keith Frankish, Christopher Hill, and Stephen Yablo; and critics who question the logical validity of the argument include George Bealer.
In his 2019 update to the article on philosophical zombies in the Stanford Encyclopedia of Philosophy, Kirk summed up the current state of the debate:
In spite of the fact that the
arguments on both sides have become increasingly sophisticated — or
perhaps because of it — they have not become more persuasive. The pull
in each direction remains strong.
A 2013 survey of professional philosophers conducted by Bourget and Chalmers produced the following results:
35.6% said P Zombies were conceivable but not metaphysically possible;
23.3% said they were metaphysically possible; 16.0% said they were
inconceivable; and 25.1% responded "other."
Types of zombies
Though
philosophical zombies are widely used in thought experiments, the
detailed articulation of the concept is not always the same. P-zombies
were introduced primarily to argue against specific types of physicalism
such as behaviorism,
according to which mental states exist solely as behavior. Belief,
desire, thought, consciousness, and so on, are only behavior (whether
external behavior or internal behavior) or tendencies towards behaviors.
A p-zombie that is behaviorally indistinguishable from a normal human
being but lacks conscious experiences is therefore not logically
possible according to the behaviorist,
so an appeal to the logical possibility of a p-zombie furnishes an
argument that behaviorism is false. Proponents of zombie arguments
generally accept that p-zombies are not physically possible, while opponents necessarily deny that they are metaphysically or, in some cases, even logically possible.
The unifying idea of the zombie is that of a human completely
lacking conscious experience. It is possible to distinguish various
zombie sub-types used in different thought experiments as follows:
A behavioral zombie that is behaviorally indistinguishable from a human.
A neurological zombie that has a human brain and is generally physiologically indistinguishable from a human.
A zombie universe that is identical to our world in all physical ways, except no being in that world has qualia.
Zombie arguments
Zombie
arguments often support lines of reasoning that aim to show that
zombies are metaphysically possible in order to support some form of dualism – in this case the view that the world includes two kinds of substance (or perhaps two kinds of property): the mental and the physical.
In contrast to dualism, in physicalism, material facts determine
all other facts. Since any fact other than that of consciousness may be
held to be the same for a p-zombie and for a normal conscious human, it
follows that physicalism must hold that p-zombies are either not
possible or are the same as normal humans.
The zombie argument is a version of general modal arguments against physicalism such as that of Saul Kripke. Further such arguments were notably advanced in the 1970s by Thomas Nagel (1970; 1974) and Robert Kirk (1974) but the general argument was most famously developed in detail by David Chalmers in The Conscious Mind (1996).
According to Chalmers one can coherently conceive of an entire
zombie world, a world physically indistinguishable from this world but
entirely lacking conscious experience. The counterpart of every
conscious being in our world would be a p-zombie. Since such a world is
conceivable, Chalmers claims, it is metaphysically possible, which is
all the argument requires. Chalmers states: "Zombies are probably not
naturally possible: they probably cannot exist in our world, with its
laws of nature." The outline structure of Chalmers' version of the zombie argument is as follows;
According to physicalism, all that exists in our world (including consciousness) is physical.
Thus, if physicalism is true, a metaphysically possible world in
which all physical facts are the same as those of the actual world must
contain everything that exists in our actual world. In particular,
conscious experience must exist in such a possible world.
In fact we can conceive of a world physically indistinguishable from
our world but in which there is no consciousness (a zombie world). From
this (so Chalmers argues) it follows that such a world is
metaphysically possible.
The above is a strong formulation of the zombie argument. There are
other formulations of the zombies-type argument which follow the same
general form. The premises of the general zombies argument are implied
by the premises of all the specific zombie arguments.
A general zombies argument is in part motivated by potential
disagreements between various anti-physicalist views. For example, an
anti-physicalist view can consistently assert that p-zombies are
metaphysically impossible but that inverted qualia (such as inverted
spectra) or absent qualia (partial zombiehood) are metaphysically
possible. Premises regarding inverted qualia or partial zombiehood can
substitute premises regarding p-zombies to produce variations of the
zombie argument.
The metaphysical possibility of a physically indistinguishable
world with either inverted qualia or partial zombiehood would imply that
physical truths don't metaphysically necessitate phenomenal truths.
To formulate the general form of the zombies argument, take the
sentence 'P' to be true if and only if the conjunct of all microphysical
truths of our world obtain, take the sentence 'Q' to be true if some
phenomenal truth, that obtains in the actual world, obtains. The general
argument goes as follows.
It is conceivable that P is true and Q is not true.
If it is conceivable that P is true and Q is not true then it is metaphysically possible that P is true and Q not true.
If it is metaphysically possible that P is true and Q is not true then physicalism is false.
Therefore, physicalism is false.
Q can be false in a possible world if any of the following obtains:
(1) there exists at least one invert relative to the actual world (2)
there is at least one absent quale relative to the actual world (3) all
actually conscious beings are p-zombies (all actual qualia are absent
qualia).
Another way to construe the zombie hypothesis is epistemically – as a problem of causal explanation, rather than as a problem of logical or metaphysical possibility. The "explanatory gap" – also called the "hard problem of consciousness" – is the claim that (to date) no one has provided a convincing causal explanation of how and why we are conscious.
It is a manifestation of the very same gap that (to date) no one has
provided a convincing causal explanation of how and why we are not
zombies.
Responses
Galen Strawson
argues that it is not possible to establish the conceivability of
zombies, so that the argument, lacking its first premise, can never get
going.
Chalmers has argued that zombies are conceivable, saying "it
certainly seems that a coherent situation is described; I can discern no
contradiction in the description."
Many physicalist philosophers have argued that this scenario eliminates itself by its description;
the basis of a physicalist argument is that the world is defined
entirely by physicality; thus, a world that was physically identical
would necessarily contain consciousness, as consciousness would
necessarily be generated from any set of physical circumstances
identical to our own.
The zombie argument claims that one can tell by the power of
reason that such a "zombie scenario" is metaphysically possible.
Chalmers states; "From the conceivability of zombies, proponents of the
argument infer their metaphysical possibility"
and argues that this inference, while not generally legitimate, is
legitimate for phenomenal concepts such as consciousness since we must
adhere to "Kripke's insight that for phenomenal concepts, there is no
gap between reference-fixers and reference (or between primary and
secondary intentions)."
That is, for phenomenal concepts, conceivability implies
possibility. According to Chalmers, whatever is logically possible is
also, in the sense relevant here, metaphysically possible.
Another response is the denial of the idea that qualia and
related phenomenal notions of the mind are in the first place coherent
concepts. Daniel Dennett and others argue that while consciousness and subjective experience
exist in some sense, they are not as the zombie argument proponent
claims. The experience of pain, for example, is not something that can
be stripped off a person's mental life without bringing about any
behavioral or physiological differences. Dennett believes that
consciousness is a complex series of functions and ideas. If we all can
have these experiences the idea of the p-zombie is meaningless.
Dennett argues that "when philosophers claim that zombies are
conceivable, they invariably underestimate the task of conception (or
imagination), and end up imagining something that violates their own
definition". He coined the term "zimboes" – p-zombies that have second-order beliefs – to argue that the idea of a p-zombie is incoherent; "Zimboes thinkZ they are conscious, thinkZ they have qualia, thinkZ
they suffer pains – they are just 'wrong' (according to this lamentable
tradition), in ways that neither they nor we could ever discover!".
Michael Lynch
agrees with Dennett, arguing that the zombie conceivability argument
forces us to either question whether or not we actually have
consciousness or accept that zombies are not possible. If zombies
falsely believe they are conscious, how can we be sure we are not
zombies? We may believe we are experiencing conscious mental states
when, in fact, we merely hold a false belief. Lynch thinks denying the
possibility of zombies is more reasonable than questioning our own
consciousness.
Furthermore, when concept of self is deemed to correspond to
physical reality alone (reductive physicalism), philosophical zombies
are denied by definition. When a distinction is made in one's mind
between a hypothetical zombie and oneself (assumed not to be a zombie),
the hypothetical zombie, being a subset of the concept of oneself, must
entail a deficit in observables (cognitive systems), a "seductive error" contradicting the original definition of a zombie.
Thomas Metzinger
dismisses the argument as no longer relevant to the consciousness
community, calling it a weak argument that covertly relies on the
difficulty in defining "consciousness", calling it an "ill-defined folk
psychological umbrella term".
Verificationism
states that, for words to have meaning, their use must be open to
public verification. Since it is assumed that we can talk about our
qualia, the existence of zombies is impossible.
Artificial intelligence researcher Marvin Minsky saw the argument as circular.
The proposition of the possibility of something physically identical to
a human but without subjective experience assumes that the physical
characteristics of humans are not what produces those experiences, which
is exactly what the argument was claiming to prove.
Richard Brown agrees that the zombie argument is circular. To show this, he proposes "zoombies", which are creatures nonphysically
identical to people in every way and lacking phenomenal consciousness.
If zoombies existed, they would refute dualism because they would show
that consciousness is not nonphysical, i.e., is physical. Paralleling
the argument from Chalmers: It's conceivable that zoombies exist, so
it's possible they exist, so dualism is false. Given the symmetry
between the zombie and zoombie arguments, we can't arbitrate the
physicalism/dualism question a priori.
Similarly, Gualtiero Piccinini
argues that the zombie conceivability argument is circular. Piccinini’s
argument questions whether the possible worlds where zombies exist are accessible
from our world. If physicalism is true in our world, then physicalism
is one of the relevant facts about our world for determining whether a
possible zombie world is accessible from our world. Therefore, asking
whether zombies are metaphysically possible in our world is equivalent
to asking whether physicalism is true in our world.
Stephen Yablo's (1998) response is to provide an error theory
to account for the intuition that zombies are possible. Notions of
what counts as physical and as physically possible change over time so conceptual analysis
is not reliable here. Yablo says he is "braced for the information that
is going to make zombies inconceivable, even though I have no real idea
what form the information is going to take."
The zombie argument is difficult to assess because it brings to
light fundamental disagreements about the method and scope of philosophy
itself and the nature and abilities of conceptual analysis. Proponents
of the zombie argument may think that conceptual analysis is a central
part of (if not the only part of) philosophy and that it certainly can
do a great deal of philosophical work. However others, such as Dennett, Paul Churchland and W.V.O. Quine, have fundamentally different views. For this reason, discussion of the zombie argument remains vigorous in philosophy.
Some accept modal
reasoning in general but deny it in the zombie case. Christopher S.
Hill and Brian P. Mclaughlin suggest that the zombie thought experiment
combines imagination of a "sympathetic" nature (putting oneself in a
phenomenal state) and a "perceptual" nature (imagining becoming aware of
something in the outside world). Each type of imagination may work on
its own, but they're not guaranteed to work when both used at the same
time. Hence Chalmers's argument needn't go through.
Moreover, while Chalmers defuses criticisms of the view that
conceivability can tell us about possibility, he provides no positive
defense of the principle. As an analogy, the generalized continuum hypothesis
has no known counterexamples, but this doesn't mean we must accept it.
And indeed, the fact that Chalmers concludes we have epiphenomenal
mental states that don't cause our physical behavior seems one reason to
reject his principle.
Related thought-experiments
Frank Jackson's Mary's room
argument is based around a hypothetical scientist, Mary, who is forced
to view the world through a black-and-white television screen in a black
and white room. Mary is a brilliant scientist who knows everything
about the neurobiology of vision. Even though Mary knows everything
about color and its perception (e.g. what combination of wavelengths
makes the sky seem blue), she has never seen color. If Mary were
released from this room and were to experience color for the first time,
would she learn anything new? Jackson initially believed this supported
epiphenomenalism (mental phenomena are the effects, but not the causes, of physical phenomena) but later changed his views to physicalism, suggesting that Mary is simply discovering a new way for her brain to represent qualities that exist in the world.
Swampman is an imaginary character introduced by Donald Davidson.
If Davidson goes hiking in a swamp and is struck and killed by a
lightning bolt while nearby another lightning bolt spontaneously
rearranges a bunch of molecules so that, entirely by coincidence, they
take on exactly the same form that Davidson's body had at the moment of
his untimely death then this being, 'Swampman', has a brain structurally
identical to that which Davidson had and will thus presumably behave
exactly like Davidson. He will return to Davidson's office and write the
same essays he would have written, recognize all of his friends and
family and so forth.
John Searle's Chinese room argument deals with the nature of artificial intelligence:
it imagines a room in which a conversation is held by means of written
Chinese characters that the subject cannot actually read, but is able to
manipulate meaningfully using a set of algorithms.
Searle holds that a program cannot give a computer a "mind" or
"understanding", regardless of how intelligently it may make it behave. Stevan Harnad argues that Searle's critique is really meant to target functionalism and computationalism, and to establish neuroscience as the only correct way to understand the mind.
Physicist Adam Brown has suggested constructing a type of philosophical zombie using Counterfactual quantum computation,
a technique in which a computer is placed into a superposition of
running and not running. If the program being executed is a brain
simulation, and if one makes the further assumption that brain
simulations are conscious, then the simulation can have the same output
as a conscious system, yet not be conscious.
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