In
philosophy
Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...
, supervenience refers to a relation between sets of properties or sets of facts. X is said to supervene on Y if and only if some difference in Y is necessary for any difference in X to be possible. Some examples include:
* Whether there is a table in the living room supervenes on the positions of molecules in the living room.
* The truth value of (A) supervenes on the truth value of (¬A). For the same reason, the truth value of (¬A) supervenes on that of (A).
* Properties of individual molecules supervene on the properties of individual atoms.
* One's moral character supervenes on one's action(s).
These are examples of supervenience because in each case the truth values of some propositions cannot vary unless the truth values of some other propositions vary.
Supervenience is of interest to philosophers because it differs from other nearby relations, for example
entailment
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 one ...
. Some philosophers believe it possible for some A to supervene on some B without being entailed by B. In such cases it may seem puzzling why A should supervene on B and equivalently why changes in A should require changes in B. Two important applications of supervenience involve cases like this. One of these is the supervenience of mental properties (like the sensation of pain) on physical properties (like the firing of 'pain neurons'). A second is the supervenience of normative facts (facts about how things ought to be) on natural facts (facts about how things are).
These applications are elaborated below. But an illustrative note bears adding here. It is sometimes claimed that what is at issue in these problems is the supervenience claim itself. For example, it has been claimed that what is at issue with respect to
the mind-body problem is whether mental phenomena do in fact supervene on physical phenomena. This is incorrect. It is by and large agreed that some form of supervenience holds in these cases: Pain happens when the appropriate neurons fire. The disagreement is over why this is so. Materialists claim that we observe supervenience because the neural phenomena entail the mental phenomena, while
dualists deny this. The dualist's challenge is to explain supervenience without entailment.
The problem is similar with respect to the supervenience of normative facts on natural facts. Discussing the ''
is-ought problem'' it is agreed that facts about how persons ought to act are not entailed by natural facts but cannot vary unless natural facts vary, and this rigid binding without entailment might seem puzzling.
The possibility of "supervenience without entailment" or "supervenience without
reduction" is contested territory among philosophers.
History
Supervenience, which means literally "coming or occurring as something novel, additional, or unexpected",
[Horgan, Terry (1993) "From supervenience to superdupervenience: meeting the demands of a material world." ''Mind.'' 102: 555-86.] from "super," meaning on, above, or additional, and "venire," meaning to come in Latin, shows occurrences in the
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a com ...
dating back to 1844.
Its systematic use in philosophy is considered to have begun in early 20th-century
meta-ethics
In metaphilosophy and ethics, meta-ethics is the study of the nature, scope, and meaning of moral judgment. It is one of the three branches of ethics generally studied by philosophers, the others being normative ethics (questions of how one ought ...
and
emergentism
In philosophy, emergentism is the belief in emergence, particularly as it involves consciousness and the philosophy of mind. 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 int ...
. As
G.E. Moore
George Edward Moore (4 November 1873 – 24 October 1958) was an English philosopher, who with Bertrand Russell, Ludwig Wittgenstein and earlier Gottlob Frege was among the founders of analytic philosophy. He and Russell led the turn from ideal ...
wrote in 1922, "if a given thing possesses any kind of intrinsic value in a certain degree, then... anything ''exactly like it'', must, under all circumstances, possess it in exactly the same degree" (p. 261).
This usage also carried over into the work of
R. M. Hare
Richard Mervyn Hare (21 March 1919 – 29 January 2002), usually cited as R. M. Hare, was a British moral philosopher who held the post of White's Professor of Moral Philosophy at the University of Oxford from 1966 until 1983. He subseque ...
. For discussion of the emergentist roots of supervenience se
Stanford Encyclopedia of Philosophy: Supervenience
In the 1970s,
Donald Davidson was the first to use the term to describe a broadly physicalist (and non-reductive) approach to the philosophy of mind, called ''
anomalous monism Anomalous monism is a philosophical thesis about the mind–body relationship. It was first proposed by Donald Davidson in his 1970 paper "Mental Events". The theory is twofold and states that mental events are identical with physical events, and ...
''. As he said in 1970, "supervenience might be taken to mean that there cannot be two events alike in all physical respects but differing in some mental respects, or that an object cannot alter in some mental respects without altering in some physical respects."
[Davidson, Donald (1970) "Mental Events." Reprinted in ''Essays on Actions and Events''. Oxford: Clarendon Press]
In subsequent years Terence ("Terry") Horgan,
David Lewis, and especially
Jaegwon Kim
Jaegwon Kim (September 12, 1934 – November 27, 2019) was a Korean-American philosopher. At the time of his death, Kim was an emeritus professor of philosophy at Brown University. He also taught at several other leading American universities ...
formalized the concept and began applying it to many issues in the philosophy of mind. This raised numerous questions about how various formulations relate to one another, how adequate the formulation is to various philosophical tasks (in particular, the task of formulating
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 ...
), and whether it avoids or entails
reductionism
Reductionism is any of several related philosophical ideas regarding the associations between phenomena which can be described in terms of other simpler or more fundamental phenomena. It is also described as an intellectual and philosophical pos ...
.
Definitions
In the contemporary literature, there are two primary (and non-equivalent) formulations of supervenience (for both definitions let A and B be sets of properties).
(1) A-properties supervene on B-properties if and only if all things that are B-indiscernible are A-indiscernible. Formally:
*
(2) A-properties supervene on B-properties if and only if anything that has an A-property has some B-property such that anything that has that B-property also has that A-property. Formally:
*
For example, if one lets A be a set of mental properties, lets B be a set of physical properties, and chooses a
domain of discourse
In the formal sciences, the domain of discourse, also called the universe of discourse, universal set, or simply universe, is the set of entities over which certain variables of interest in some formal treatment may range.
Overview
The domain ...
consisting of persons, then (1) says that any two persons who are physically indiscernible are mentally indiscernible, and (2) says that any person who has a mental property has some physical property such that any person with that physical property has that mental property.
Some points of clarification: first, the definitions above involve quantification over properties and hence
higher-order logic
mathematics and logic, a higher-order logic is a form of predicate logic that is distinguished from first-order logic by additional quantifiers and, sometimes, stronger semantics. Higher-order logics with their standard semantics are more express ...
. Second, in (1), expressions of the form
capture the concept of sharing all properties, or being
indiscernible
In mathematical logic, indiscernibles are objects that cannot be distinguished by any property or relation defined by a formula. Usually only first-order formulas are considered. Examples
If ''a'', ''b'', and ''c'' are distinct and is a set ...
with respect to a set of properties. Thus, (1) can be understood more intuitively as the claim that all objects that are indiscernible with respect to a base set of properties are indiscernible with respect to a supervenient set of properties, or, as it is also sometimes said, that B-twins are A-twins. Finally, supervenience claims typically involve some modal force, however, the way that
modal force is specified depends on which more specific variety of supervenience one decides upon (see below).
(1) and (2) are sometimes called "schemata" because they do not correspond to actual supervenience relations until the sets of properties A and B, the
domain
Domain may refer to:
Mathematics
*Domain of a function, the set of input values for which the (total) function is defined
**Domain of definition of a partial function
**Natural domain of a partial function
**Domain of holomorphy of a function
* Do ...
of entities to which those properties apply, and a modal force have been specified. For modal forms of supervenience, the modal strength of the relation is usually taken to be a parameter (that is, the possible worlds appealed to may be physically possible, logically possible, etc.). Also, note that in the early literature properties were not always central, and there remain some who prefer to frame the relation in terms of
predicates
Predicate or predication may refer to:
* Predicate (grammar), in linguistics
* Predication (philosophy)
* several closely related uses in mathematics and formal logic:
**Predicate (mathematical logic)
**Propositional function
**Finitary relation, ...
,
fact
A fact is a datum about one or more aspects of a circumstance, which, if accepted as true and proven true, allows a logical conclusion to be reached on a true–false evaluation. Standard reference works are often used to check facts. Scient ...
s, or
entities
An entity is something that exists as itself, as a subject or as an object, actually or potentially, concretely or abstractly, physically or not. It need not be of material existence. In particular, abstractions and legal fictions are usually ...
instead, for example.
Varieties of supervenience
Beginning in the 1980s, inspired largely by
Jaegwon Kim
Jaegwon Kim (September 12, 1934 – November 27, 2019) was a Korean-American philosopher. At the time of his death, Kim was an emeritus professor of philosophy at Brown University. He also taught at several other leading American universities ...
's work, philosophers proposed many varieties of supervenience, which
David Lewis called the "unlovely proliferation".
[Lewis, David (1986) '']On the Plurality of Worlds
''On the Plurality of Worlds'' (1986) is a book by the philosopher David Lewis that defends the thesis of modal realism. "The thesis states that the world we are part of is but one of a plurality of worlds," as he writes in the preface, "an ...
''. Oxford: Oxford University Press. These varieties are based both on (1) and (2) above, but because (1) is more common we shall focus on varieties of supervenience based on it.
We can begin by distinguishing between local and global supervenience:
* Local: For any two objects x and y, if x and y are base-indiscernible, they are supervenient-indiscernible.
For example, if mental states locally supervene on brain states, then being in the same brain state entails being in the same mental state.
* Global: For any two worlds w1 and w2, if w1 and w2 are base-indiscernible, they are supervenient-indiscernible.
For example, if psychological properties globally supervene on physical properties, then any two worlds physically the same will be psychologically the same. The value of global supervenience is that it allows for supervenient properties to be determined not by local properties of an individual thing alone, but by some wider spatiotemporal distribution of things and properties. For example, something's being a dollar bill depends not only on the paper and the inks it is made out of, but also on a widely dispersed variety of features of the world it occupies.
Both local and global supervenience come in many forms. Local supervenience comes in strong and weak varieties:
* Weak: For any world w, and for any two objects x in w and y in w, if x and y are base-indiscernible, they are supervenient-indiscernible.
* Strong: For any worlds w1 and w2, and for any two objects x in w1 and y in w2, if x and y are base-indiscernible, they are supervenient-indiscernible.
The difference is essentially whether correlations between base and supervenient properties hold within actual worlds only, or across possible worlds. For example, if psychological properties strongly locally supervene on physical properties, then any two people physically the same, in any two worlds, will also be psychologically the same. On the other hand, if psychological properties only weakly locally supervene on physical properties, then those correlations between base and supervenient properties that hold in virtue of the supervenience relation are maintained within each world, but can be different in different worlds. For example, my physical duplicates in the actual world will have the same thoughts as I have; but my physical duplicates in other possible worlds may have different thoughts than I have in the actual world.
There are also several kinds of global supervenience relations, which were introduced to handle cases in which worlds are the same at the base level and also at the supervenient level, but where the ways the properties are connected and distributed in the worlds differ. For example, it is consistent with global mental–physical supervenience on the simple formulation described above for two worlds to have the same number of people in the same physical states, but for the mental states to be distributed over those people in different ways (e.g. I have my father's thoughts in the other world, and he has my thoughts). To handle this, property-preserving isomorphisms (1-1 and onto functions between the objects of two worlds, whereby an object in one world has a property if and only if the object which that function takes you to in the other world does) are used, and once this is done, several varieties of global supervenience can be defined.
Other varieties of supervenience include multiple-domains supervenience and similarity-based supervenience.
Examples of supervenient properties
Value properties
The
value
Value or values may refer to:
Ethics and social
* Value (ethics) wherein said concept may be construed as treating actions themselves as abstract objects, associating value to them
** Values (Western philosophy) expands the notion of value beyo ...
of a physical object to an
agent
Agent may refer to:
Espionage, investigation, and law
*, spies or intelligence officers
* Law of agency, laws involving a person authorized to act on behalf of another
** Agent of record, a person with a contractual agreement with an insuranc ...
is sometimes held to be supervenient upon the physical properties of the object. In
aesthetics
Aesthetics, or esthetics, is a branch of philosophy that deals with the nature of beauty and taste, as well as the philosophy of art (its own area of philosophy that comes out of aesthetics). It examines aesthetic values, often expressed thr ...
, the
beauty
Beauty is commonly described as a feature of objects that makes these objects pleasurable to perceive. Such objects include landscapes, sunsets, humans and works of art. Beauty, together with art and taste, is the main subject of aesthetics, o ...
of
La Grande Jatte
LA most frequently refers to Los Angeles, the second largest city in the United States.
La, LA, or L.A. may also refer to:
Arts and entertainment Music
* La (musical note), or A, the sixth note
* "L.A.", a song by Elliott Smith on ''Figur ...
might supervene on the physical composition of the painting (the specific
molecules
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
that make up the painting), the artistic composition of the painting (in this case,
dots
Directly observed treatment, short-course (DOTS, also known as TB-DOTS) is the name given to the tuberculosis (TB) control strategy recommended by the World Health Organization. According to WHO, "The most cost-effective way to stop the spread of T ...
), the figures and forms of the painted image, or the painted canvas as a whole. In
ethics
Ethics or moral philosophy is a branch of philosophy that "involves systematizing, defending, and recommending concepts of right and wrong behavior".''Internet Encyclopedia of Philosophy'' The field of ethics, along with aesthetics, concerns m ...
, the
goodness of an act of
charity
Charity may refer to:
Giving
* Charitable organization or charity, a non-profit organization whose primary objectives are philanthropy and social well-being of persons
* Charity (practice), the practice of being benevolent, giving and sharing
* Ch ...
might supervene on the physical properties of the agent, the mental state of the agent (his or her intention), or the external
state of affairs itself. Similarly, the overall suffering caused by an earthquake might supervene on the spatiotemporal entities that constituted it, the deaths it caused, or the natural disaster itself. The claim that moral properties are supervenient upon non-moral properties is called
moral supervenience.
Mental properties
In
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 ...
, many philosophers make the general claim that the mental supervenes on the physical. In its most recent form this position derives from the work of
Donald Davidson, although in more rudimentary forms it had been advanced earlier by others. The claim can be taken in several senses, perhaps most simply in the sense that the mental ''properties'' of a person are supervenient on their physical ''properties''. Then:
* If two persons are indistinguishable in all of their physical properties, they must also be indistinguishable in all of their mental properties.
An alternative claim, advanced especially by
John Haugeland
John Haugeland (; March 13, 1945 – June 23, 2010) was a professor of philosophy, specializing in the philosophy of mind, cognitive science, phenomenology, and Heidegger. He spent most of his career at the University of Pittsburgh, followed by ...
, is a kind of ''weak local'' supervenience claim; or, weaker still, mere ''global'' supervenience. The claim that mental properties supervene globally on physical properties requires only a quite modest commitment: any difference between two possible worlds with respect to their instantiated mental properties entails at least ''some'' difference in the physical properties instantiated in those two worlds. Importantly, it does ''not'' require that the mental properties of an individual person supervene ''only'' on that person's physical state.
This weak global thesis is particularly important in the light of
direct reference A direct reference theory (also called referentialism or referential realism)Andrea Bianchi (2012) ''Two ways of being a (direct) referentialist'', in Joseph Almog, Paolo Leonardi, ''Having in Mind: The Philosophy of Keith Donnellan''p. 79/ref> is a ...
theories, and
semantic externalism
In the philosophy of language, semantic externalism (the opposite of semantic internalism) is the view that the meaning of a term is determined, in whole or in part, by factors external to the speaker. According to an externalist position, one can ...
with regard to the content both of words and (more relevant to our concerns here) of ''thoughts''. Imagine two persons who are indistinguishable in their local physical properties. One has a dog in front of his eyes and the other has a dog-image artificially projected onto his retinae. It might be reasonable to say that the former is in the ''mental state'' of seeing a dog (and of knowing that he does so), whereas the latter is not in such a state of seeing a dog (but falsely believes that he sees one).
There is also discussion among philosophers about mental supervenience and our experience of duration. If all mental properties supervene only upon some physical properties at durationless moments, then it may be difficult to explain our experience of duration. The philosophical belief that mental and physical events exist as a series of durationless moments that lie between the physical past and the physical future is known as
presentism.
Computational properties
There are several examples of supervenience to be found in
computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
ing. For example, in a dial-up internet connection, the audio signal on a phone line transports
IP packets between the user's computer and the
Internet service provider
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise private ...
's computer. In this case, the arrangement of bytes in that packet supervenes on the physical properties of the phone signal. More generally, each layer of the
OSI Model
The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communications ...
of computer networking supervenes on the layers below it.
We can find supervenience wherever a message is conveyed by a representational medium. When we see a letter "a" in a page of print, for example, the meaning ''Latin lowercase "a"'' supervenes on the geometry of the boundary of the printed
glyph
A glyph () is any kind of purposeful mark. In typography, a glyph is "the specific shape, design, or representation of a character". It is a particular graphical representation, in a particular typeface, of an element of written language. A g ...
, which in turn supervenes on the ink deposition on the paper.
Biological properties
In biological systems
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
can be said to supervene on
genotype
The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...
. This is because any genotype encodes a finite set of unique phenotypes, but any given phenotype is not produced by a finite set of genotypes. Innumerable examples of
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
can be used to support this claim. Throughout nature, convergent evolution produces incredibly similar phenotypes from a diverse set of taxa with fundamentally different genotypes underpinning the phenotypes. One example is
evolution on islands which is a remarkably predictable example of convergent evolution where the same phenotypes consistently evolve for the same reasons. Organisms released from predation tend to become larger, while organisms limited by food tend to become smaller. Yet there are almost infinite numbers of genetic changes that might lead to changes in body size. Another example of convergent evolution is the loss of sight that almost universally occurs in
cave fish
Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish and hypog ...
living in lightless pools. Eyes are expensive, and in lightless cave pools there is little reason for fish to have eyes. Yet, despite the remarkably consistent convergent evolution producing sightless cave fish, the genetics that produce the loss of sight phenotype is different nearly every time. This is because phenotype supervenes on genotype.
Arguments against supervenience-based formulations of physicalism
Although supervenience seems to be perfectly suited to explain the predictions of physicalism (i.e. the mental is dependent on the physical), there are four main problems with it. They are ''Epiphenomenal ectoplasm'', the ''lone ammonium molecule problem'', ''modal status problem'' and the ''problem of necessary beings.''
Epiphenomenal ectoplasm
''
Epiphenomenal ectoplasm'' was proposed by Horgan and Lewis in 1983; they envisioned a possible world (a world that could possibly exist) ''W'' which is identical to our world in the distribution of all mental and physical characteristics (i.e. they are identical), except world ''W'' contains an experience called ''epiphenomenal ectoplasm'' that does not causally interact with that world. The possibility of such a world should be compatible with physicalism as this is a property of the actual world; but a supervenience-based definition of physicalism would imply that such a world could not exist, because it differs from the actual world with respect to a mental property, but is physically identical.
A typical response to this objection is
Frank Jackson's;
he adjusted the supervenience-based definition of physicalism to state "Physicalism is true at a possible world ''W'' if and only if any world which is a minimal physical duplicate (i.e. is physically identical) of ''W'' is a duplicate of ''W simpliciter.''" This avoids the problem because the "ectoplasm" world is not a minimal physical duplicate, so its identity with the actual world need not follow.
The lone ammonium molecule problem
The ''lone ammonium molecule problem'' provides a problem for Jackson's solution to ''epiphenomenal ectoplasm''. It was proposed by
Jaegwon Kim
Jaegwon Kim (September 12, 1934 – November 27, 2019) was a Korean-American philosopher. At the time of his death, Kim was an emeritus professor of philosophy at Brown University. He also taught at several other leading American universities ...
in 1993 when he stated that according to Jackson's idea of supervenience, a possible world ''W'' was identical to the actual world, except it possessed an extra ammonium molecule on one of Saturn's rings. This may not seem to provide much of a problem, but because Jackson's solution refers only to minimal physical duplicates, this allows for the mental properties of ''W'' to be vastly different from those in the actual world. If such a difference would cause mental differences on Earth, it would not be consistent with our understanding of physicalism.
Modal status
Suppose that the supervenience thesis for physicalism is stated as a
nomological
In philosophy, nomology refers to a "science of laws" based on the theory that it is possible to elaborate descriptions dedicated not to particular aspects of reality but inspired by a scientific vision of universal validity expressed by scientific ...
constraint, rather than a metaphysical one; this avoids any objection based on the thesis ruling out metaphysical possibilities which a physicalist would leave open. But the thesis would not rule out the metaphysical possibility of
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 consciousness, conscious ex ...
, although their impossibility is a clear consequence of physicalism.
Problem of necessary beings
The ''problem of necessary beings'' was proposed by Jackson in 1998,
[ in which he stated that the existence of a non-physical ]necessary being
A cosmological argument, in natural theology, is an argument which claims that the existence of God can be inferred from facts concerning causation, explanation, change, motion, contingency, dependency, or finitude with respect to the universe o ...
(in all possible worlds) would prove physicalism false. However, physicalism allows for the existence of necessary beings, because any minimal physical duplicate would have the same necessary being as the actual world. This however is paradox
A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly self-contradictory or a logically u ...
ical, based on the fact that physicalism both permits and prevents the existence of such beings.
See also
* Functionalism (philosophy of mind)
In philosophy of mind, functionalism is the thesis that mental states (beliefs, desires, being in pain, etc.) are constituted solely by their functional role, which means, their causal relations with other mental states, sensory inputs and behavio ...
* Emergentism
In philosophy, emergentism is the belief in emergence, particularly as it involves consciousness and the philosophy of mind. 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 int ...
* Downward causation In philosophy, downward causation is a causal relationship from higher levels of a system to lower-level parts of that system: for example, mental events acting to cause physical events. The term was originally coined in 1974 by the philosopher and ...
Notes
External links
*
*
*
*
* {{InPho, taxonomy, 2213
Concepts in logic
Concepts in metaphysics
Concepts in the philosophy of mind
Concepts in the philosophy of science
Metaphysical theories
Metaphysics of mind
Ontology
Physicalism