Supervenience

Supervenience (Latin from super “over”, “additional” and venire “come”) is a philosophical technical term that is used to describe relationships between properties . It plays a particularly prominent role in metaethics and the philosophy of mind and is used there to describe the relationship between moral or mental properties and physical properties. The question of the correct interpretation of the presumed supervenience relationship is often seen as crucial for the plausibility of reductionism and physicalism .

Basic idea

The basic idea of ​​the supervenience concept is as follows: A set A of properties supervises over a set B of properties if and only if a change in A is accompanied by changes in B, but not necessarily vice versa. In other words, you cannot change A without changing B.

An example: A photograph has the property of depicting a rabbit. This property cannot be changed without changing the physical properties of the image. In this sense, the depicting properties supervise the physical properties of the image. Conversely, however, the physical properties do not supervise the representational properties, since it is possible to create a rabbit picture with a slightly different arrangement of physical particles.

The philosopher David Lewis describes this relationship as follows:

A dot-matrix picture has global properties — it is symmetrical, it is cluttered, and whatnot — and yet all there is to the picture is dots and non-dots at each point of the matrix. The global properties are nothing but patterns in the dots. They supervene: no two pictures could differ in their global properties without differing, somewhere, in whether there is or there isn't a dot.		A bitmap image has global properties - it's symmetrical, it's messed up, whatever - and yet in this image everything is dots and non-dots at every dot of the matrix. The global properties are nothing but patterns of points. They supervise: no two pictures could differ in their global properties without being different somewhere in whether there is a point or not.

For the philosophical debate it is now crucial that it is assumed that moral and mental properties also supervise physical properties: if two situations are absolutely identical in physical respect, they also seem to be indistinguishable in moral or mental respect. Modern empirical findings speak in favor of psychophysical supervenience: Imaging methods show that changes in consciousness go hand in hand with changes in neuronal processes.

The central philosophical question is how the supervenience relationships can be understood. Reductionists explain that mental states supervise over physical states, since they are nothing but the physical states and can therefore also be traced back to them. If the mental is nothing but the physical, it is no longer a mystery that the mental cannot be changed without changing the physical at the same time. Critics of this position must provide another explanation for the supervenience relationship. Some anti-reductionists claim that the mental states are linked by a fundamental, psychophysical law of nature to the neural states over which they supervise. Other anti-reductionists deny that there is a supervenience relationship between the mental and the physical.

History of the concept of supervenience

Early Uses

The earliest recorded use of the adjective "supervenient" dates from 1594, the noun "supervenience" is documented for the year 1664. Even if the term supervenience was also used quite early in the philosophical debate, for example by Gottfried Wilhelm Leibniz , it had a different meaning then than it does today. Until well into the 20th century, “supervenience” was understood more in the sense of “something additional”; today it is understood to mean the relationship between entities described above.

A mediating position between the historical and the modern concept of supervenience can be found among the British emergentists. The central thesis of this school was that there are emergent properties. This means that there are properties that result from a complex physical system , but at the same time are irreducible, i.e. cannot be explained by the physical components. This position is compatible with the thesis that the emergent properties - such as mental experience - in the modern sense supervise the physical properties. In fact, there is also a concept of supervenience among the emergentists, albeit more in the historical meaning of “something additional”.

Supervenience in ethics

The modern use of the supervenience concept has its origin in the metaethical debate. In particular, George Edward Moore formulated the idea of ​​supervenience early on, but without using the term supervenience. Moore stated:

[...] if a given thing possesses any kind of intrinsic value in a certain degree, then not only must that same thing posses it, under all circumstances, in the same degree, but also anything exactly like it, must, under all circumstances, posses it in exactly the same degree.		[...] if a given thing has some kind of intrinsic value to some degree, then not only must the same thing have it, under all circumstances, to the same degree, but also something exactly the same, under all circumstances, must have this in have exactly the same degree.

Moore formulated the basic idea of ​​the supervenience concept here: There can be no judgmental or moral difference in the properties of an object without there being differences in the physical properties. For Moore, this idea stood in the context of a realistic and non-reductive theory of the moral. Moore assumed that there are irreducible moral facts that are, however, in a supervenience relationship to the physical.

Another interpretation was offered by Richard Mervyn Hare , who introduced the concept of supervenience into the moral-philosophical debate. It is true that Hare also assumed that moral descriptions supercede physical descriptions. However, he stated that there are no objective moral facts in the world in the way that physical facts exist. Such an anti-realistic theory of the moral does not have to explain the supervenience relationship between moral and physical properties, since moral properties do not really exist. Today, an anti-realistic, metaethical position is represented by Simon Blackburn , for example , who argues that the supervenience relationships can only be understood within the framework of an anti-realistic theory.

Supervenience in the philosophy of mind

In the philosophy of mind , too , the concept of supervenience was first used to describe a non-reductive theory of the mental. Donald Davidson first used the supervenience concept in his 1970 essay Mental Events . This essay lays the foundation for Davidson's theory of anomalous monism . According to this theory, individual mental events ( tokens ) are identical to individual neural events. However, no class of mental events ( types such as headache or joy) is identical to a class of neural events. According to Davidson, the mismatch between the classes prevents the mental from being reduced to the physical. Nevertheless, according to Davidson, a relationship can be indicated by the concept of supervenience:

Although the position I describe denies that there are psychophysical laws, it is consistent with the view that mental characteristics are in some sense dependent or supervenient, on physical characteristics. Such supervenience might be taken to mean that there cannot be two events alike in all physical respects but differing in some mental respects [...]. Dependence or supervenience of this kind does not entail reducibility through law or definition [...].		Although the position I have described denies that there are psychophysical laws, it is consistent with the assumption that mental characteristics are in a certain sense dependent or super-subservient to physical characteristics. Such a supervenience can be described by the thesis that no two events can be the same in all physical aspects, but different in their mental aspects [...]. Dependency or supervenience of this kind does not include reducibility by law or definition [...].

Davidson's use of the term supervenience had a powerful impact on the philosophy of mind. It promised an analysis of the psychophysical relationships without implying an implausible reductionism . Jaegwon Kim provided influential interpretations of this concept of supervenience , but soon gained a skeptical distance. Kim argues that the supervenience cannot explain the psychophysical conditions, but demands an explanation itself. It is true that one can provide an answer to the question of the relationship between the mental and the physical with supervenience. However, one has to put up with the question of what kind of relationship the supervenience relationship represents. One could also ask why the mental supervises over the physical. Kim concludes that speaking of supervenience does not solve the mind-body problem , but rather formulates it: “Mind-body-supervenience, therefore, does not state a solution to the mind-body problem; rather it states the problem itself. "

Explanations for supervenience

Illustration to the question.
This representation of a drawing can be viewed as representing the edges of a cube. If you look at the cube lattice for a little longer , there is often a change in the perceived perspective, which changes the aspect.
Because of this illusion , such images are counted among the tilting figures and named Necker's cube after their description .
If the property of Necker cube is assigned to the respective depicted object, it is retained as long as its physical shape remains unchanged. In order for the depiction of the object to appear as a Necker cube - and which can be recognized as such - an observer is required.

The problem

In the philosophical debates it is generally assumed that the assertion of a supervenience relationship between A and B, on closer examination, cannot provide any satisfactory information about the relationship between A and B. Supervenancy relationships do not seem to be explanatory, but rather as descriptions of a problem to require explanations . The explanations offered for psychophysical supervenience differ depending on the metaphysical background belief. Physicalists , dualists, and non-physicalists must try to find an explanation for the psychophysical supervenience that is compatible with their metaphysics .

Physicalistic strategies

Most physicalists try to explain psychophysical supervenience through reductive analyzes: If A can be reduced to B, then it is no longer a mystery why A supervises over B. One can easily make this connection clear with examples. The property of a drop of water to be fluid supervises over the physical properties of the drop of water. One cannot change this property (by freezing or evaporating) without changing the physical structure of the water drop. But this relationship of supervenience is easy to explain. The properties of the water drop can be reduced to its physical properties. If the mental can also be reduced to the physical, this supervenience relationship could also be easily explained: The mental property M would supervise over the physical properties P1 – Pn, because M would be nothing other than P1 – Pn.

Against reductionist theories of the mental, the objection is often that there are critical features of our consciousness that make it impossible to trace back to physical structures. One question that physicalist positions must ask is whether there can be a physicalist explanation for psychophysical supervenience when reductive efforts fail. The philosopher Terence Horgan coined the term super dupervenience for the supervenience relationships that are acceptable within the framework of a physicalist metaphysics. However, he remains skeptical about the question of whether a satisfactory, non-reductive super dupervenance relationship can be found.

An anti-realistic interpretation, analogous to metaethical anti-realism (see the section on supervision in ethics ), may appear as one possibility . However, this position would amount to a denial of the existence of the mental. Few philosophers want to accept such an eliminative materialism .

Non-physicalist strategies

Psychophysical supervenience is also a challenge for non-physicalist positions. If mental states are not simply physical states, the existence of psychophysical supervenience threatens to become incomprehensible. A possible non-physicalist strategy is therefore to reject the supervenience relationship.

Other non-physicalists accept psychophysical supervenience and explain that mental states are linked to physical states by laws of nature . According to one such position the mental supervenes on the physical as the mental by the physical cause is. One also speaks of “nomological” or “natural supervenience”. David Chalmers is currently the best-known representative of such a position.

However, this position also faces difficulties. One problem is, for example, the fact that the postulated laws of nature cannot be reduced to the basic physical laws, since they link psychological and physical facts. This means that one would have to expand the world to include more fundamental natural laws, a consequence that is criticized by many philosophers as implausible. The still unanswered question is whether non-physicalists can offer a different interpretation of psychophysical supervenience.

Supervenience and Externalism

The dominant physicalist point of view in the professional world is that the mental states of a person supervise the neural states in the brain. No change in mental state occurs without a change in a brain state. On the other hand, Hilary Putnam and Tyler Burge claim to be able to show that the mental content can be influenced by the physical or even the social environment of a person without the neuronal state being influenced as a result.

The classic argument for this position (also called externalism ) is based on a thought experiment : Imagine a twin earth for our earth , which resembles the earth in almost every detail down to the subatomic particles. There is only one difference: what is H ₂ O on earth is a different substance XYZ on twin earth . Since the two worlds are otherwise identical, there is a twin B on twin earth for every person A on earth who is in exactly the same neural states. However, A and B do not have the same thought when they think "There is water". Namely, the thought of A relates to H ₂ O, while the thought of B relates to XYZ. If so, the mental cannot supervise over the neural since two people can be in the same neural state without being in the same mental state.

One could argue that a mirror world that is exact except for one molecule does not appear plausible, since the physically not insignificant difference would also have to change the physical conditions in this world - probably dramatically.

Nevertheless, this mind game was answered with the concept of global supervenience . With this thesis, the supervenience basis is expanded: The mental should no longer supervise solely over the neural states, but generally over all physical states of the world. Such a position can handle the thought experiment as there is actually a physical difference between Earth and Twin Earth. What is H ₂ O on Earth is XYZ on Twin Earth .

The objection to global supervenience was that it was insufficient for a materialistic position. After all, global supervenience is compatible with the following assumption: a twin solar system differs physically from our solar system only in that one atom is missing in the Saturn ring. Nevertheless, there are no mental states in Gemini Earth, humans are all automatons without consciousness. Since global supervenience, in contrast to materialism, seems to be compatible with such situations, it is often assumed that global supervenience cannot be successfully used in a materialistic theory.

In general, it seems to ignore the fact that a notable difference in thought - as with regard to water - would also have to be associated with a different experience and thus also with other neuronal states. If this were not the case, the thoughts of A and B regarding water would actually be identical - as unimpressed by insignificant differences. This applies particularly to the example with the missing atom in the ring of Saturn, which certainly cannot achieve any other neuronal or mental states. Thus the thought experiment as such is not valid.

The variety of supervenience terms

In the philosophical debate there are various proposals for the correct definition of the supervenience thesis. The various formulations differ on the one hand in whether they are local or global supervenience theses (see section on supervision and externalism) and on the other hand they differ in the use of modal operators or possible worlds . These suggestions, some of which are formulated at a very high technical level, vary so widely because the metaphysical background beliefs have a direct influence on the modal requirements for a correct definition of supervision. A physicalist who thinks that the mental is nothing but the physical cannot assume that psychophysical supervenience is only a contingent fact.

De facto supervenience

The weakest formulation of the supervenience thesis gets by without modal operators: The set A of properties supervises over the set B of properties, if there is no change in A, without a change in B. Here, with Ansgar Beckermann from “De-facto- Supervenience ”speak. For example: If every object that has a heart also has a kidney, then the property of having a heart supervises over the property of having a kidney. De facto supervenience in relation to the philosophy of mind would therefore simply mean: There is no change in mental properties without a change in physical properties.

Most of the time, de facto supervenience is seen as insufficient for physicalism. If B only de facto supervises over A, then this is not a necessary relationship. And that means: Just as beings with a heart but without a kidney could develop, so could beings that are physically like us but have no consciousness. A physicalist has to reject this: If mental states are identical with physical states, then the physical states cannot occur without the mental states. This lies in the logic of identity relationships , as one can easily make clear with an example: If Konrad Adenauer is identical with the first Federal Chancellor, then it is simply not possible that Konrad Adenauer is in a place that is not the first Federal Chancellor of the FRG is.

Weak and strong supervenience

In response to these problems, it is mostly assumed that an element of necessity needs to be brought into the supervenience relationship. A first formulation can look like this: The property A supervises over the set B of properties if there can be no change in A without a change in B.

However, there is still further differentiation here. The question is asked whether the supervenience thesis only applies to one or every possible world. If the first applies, one speaks with Kim of weak supervenience and distinguishes her from the strong supervenience, which also applies to all possible worlds. According to the weak supervenience thesis, there cannot be two objects in a world that are physically the same but mentally different. However, there could be an object in world w1 that is physically the same as an object in world w2, but with different mental properties. It is precisely this case that is excluded from strong supervenience, which is why it is often argued that strong supervenience alone is appropriate for physicalism.

literature

• Andreas Bartels , Manfred Stöckler (ed.): Theory of Science . mentis Verlag, Paderborn, 2009, ISBN 978-3-89785-591-5
• Ansgar Beckermann : Analytical Introduction to the Philosophy of Mind . 3rd updated and expanded edition. Walter de Gruyter, Berlin 2008, ISBN 978-3-11-020424-7 , ( De Gruyter Study Book ), (An overview of the basic ideas).
• Jaegwon Kim : Supervenience and mind. Selected philosophical essays . Cambridge University Press, Cambridge 1993, ISBN 0-521-43996-5 , ( Cambridge studies in philosophy ), (Collection of Kim's seminal papers).
• Jaegwon Kim: (Ed.): Supervenience . Ashgate, Aldershot 2002, ISBN 0-7546-2063-8 , ( The international research library of philosophy 26), (collection of texts on the subject by various authors).

swell

1. ^ Paul Hoyningen-Huene : Reduction and Emergence . In: Andreas Bartels , Manfred Stöckler (Ed.): Theory of Science . mentis Verlag, Paderborn, 2009, p. 180
2. ↑ David Lewis : Reduction of Mind ', in: Guttenplan (ed.), A Companion to the Philosophy of Mind , Oxford, Blackwell, 1994
3. ^ ^{A b} David Chalmers : The conscious Mind , Oxford, Oxford University Press, 1997, ISBN 0-19-511789-1
4. ^ ^{A b} Jaegwon Kim : Supervenience and Mind: Selected Philosophical Essays , Cambridge University Press, Cambridge and New York, 1993, ISBN 0-521-43996-5
5. ^ Gottfried Wilhelm Leibniz : in Bodermann (ed.): The Leibniz manuscripts of the royal public library in Hanover , Hanover, 1895, p. 74.
6. ^ Conwy Lloyd Morgan : Emergent Evolution , London, Williams & Norgate , 1923
7. ^ George Edward Moore : Philosophical Studies , London, 1922, p. 261.
8. ^ Richard Mervyn Hare : The Language of Morals , London, 1954
9. ↑ Simon Blackburn : The Supervenienceargument against moral Realism in: Southern Journal of Philosophy , 1992, pp. 13-38.
10. ^ Donald Davidson : Essays on Actions and Events , Oxford University Press, Oxford, 1980, ISBN 0-19-924627-0 , p. 214.
11. ↑ “Mind-body supervenience does not therefore provide a solution to the mind-body problem; rather, it specifies the problem itself. ”( Jaegwon Kim : Supervenience and Mind: Selected Philosophical Essays , Cambridge University Press, Cambridge and New York, 1993, ISBN 0-521-43996-5 , pp. 167f.)
12. ^ Terence Horgan : From Supervenience to Superdupervenience: Meeting the Demands of a Material World , Mind 102, 1993, pp. 555-86.
13. ^ Hilary Putnam : The meaning of meaning , in: Gunderson (ed.): Language, Mind and Knowledge , University of Minnesota Press, Minneapolis, 1975, pp. 215-271.
14. ^ Tyler Burge : Individualism and the Mental , in: Midwest Studies , IV, 1979
15. ↑ Ansgar Beckermann : Analytical Introduction to the Philosophy of Mind , Walter de Gruyter, Berlin, 2000
16. ^ Jaegwon Kim : Supervenience and Mind: Selected Philosophical Essays , Cambridge University Press, Cambridge and New York, 1993, ISBN 0-521-43996-5 , p. 141.

Web links

• Entry in Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .