Supervenience

Supervenience (Latin for " coming " from super "above", "additional" and venire ) is a philosophical term of art used to describe relationships between properties. He plays a prominent role, especially in meta-ethics and the philosophy of mind where it is used to describe the relationship between moral and mental properties to physical properties. The question of the correct interpretation of the alleged supervenience is often regarded as crucial to the plausibility of reductionism and physicalism.

• 3.1 The problem
• 3.2 physicalist strategies
• 3.3 Nichtphysikalistische strategies

• 5.1 De facto supervenience
• 5.2 Weak and strong supervenience

The basic idea

The basic idea of ​​Supervenienzkonzepts is as follows: A family property A supervenes if and only about a property family B, when a change is accompanied by changes in A B, but not necessarily vice versa. In other words: It is not possible to change A to B without change. An example: A picture about the property represent a hare. This property can not be changed without changing the physical properties of the image. In this sense, the performing supervene properties on the physical properties of the image. Conversely, although not supervene the physical properties over the performing characteristics because it is possible to create an image with a different rabbit array of physical particles. The philosopher David Lewis describes this relationship as follows:

For the philosophical debate is now crucial that it is believed that moral and mental properties supervene on physical properties: If two situations are absolutely identical in physical terms, they do not seem to be able to distinguish moral or mental respects. Speak in favor of psychophysical supervenience modern empirical findings: Imaging techniques show that changes in consciousness associated with changes in the neural events.

The central philosophical question is how the Supervenienzbeziehungen can be understood. Reductionists explain that mental states supervene on physical states, since they are nothing but the physical conditions and therefore can also be attributed to this. If the mental is nothing more than the physical, it is also no longer a mystery that the mental can not be changed without having to change both the physical. Critics of this position must provide another explanation for the supervenience. Some anti-reductionists is claimed that the mental states are connected by a basic, psycho-physical law of nature to the neural states, on which they supervene. Other anti-reductionists deny that the mental and physical Supervenienzverhältnis between there.

History of Supervenienzbegriffs

Early uses of

The earliest recorded use of the adjective " supervenient " dates from 1594, the noun " supervenience " is documented for the year 1664. Although the term " supervenience " has also been used quite early in the philosophical debate, such as Gottfried Wilhelm Leibniz, he had at that time a different meaning than today. While today with " supervenience " the above described relationship between entities says, had the term to the 20th century rather the meaning of " something extra ".

A mediating position between the historic and modern Supervenienzbegriff can be found in the British emergentists. The central thesis of this school was that there are emergent properties. This means that properties exist that result from a complex physical system, but at the same time are irreducible, ie can not be explained by the physical components. This position is compatible with the thesis that the emergent properties - such as the mental experience - in the modern sense supervene on the physical properties. In fact, is also found in the emergentists the notion of supervenience, but rather in the historical meaning of " something extra ".

Supervenience in ethics

The modern use of the Supervenienzkonzepts has its origins in the meta-ethical debate. In particular, George Edward Moore formulated the early Supervenienzgedanken, but without using the notion of supervenience. Moore said:

Moore formulated here the basic idea of ​​Supervenienzkonzepts: There may be no difference in the evaluative / moral properties of an object without that there are differences in the physical properties. This idea was at Moore in the context of a realistic and non-reductive theory of morality. Moore was assumed that there are irreducible moral facts are, however, in a supervenience on the physical.

Another interpretation was offered by Richard Mervyn Hare, who brought the Supervenienzbegriff in the moral-philosophical debate. Although Hare also assumed that supervene moral descriptions of physical descriptions. However, he stated that there are no objective moral facts in the world, existed as physical facts. Such an anti -realist theory of morality must not explain the supervenience between moral and physical properties because according to her, it is not really moral properties. Today, an anti -realist, metaethical position is approximately represented by Simon Blackburn, who argues that only in the context of an anti- realist theory, the Supervenienzverhältnisse are understandable.

Supervenience in the philosophy of mind

Also in the philosophy of mind of Supervenienzbegriff was first used to describe a nonreductive theory of mind. Donald Davidson used the Supervenienzkonzept the first time in his 1970 essay published Mental Events. This paper provides the foundation for Davidson's theory of the anomalous monism. According to this theory individual mental events ( token ) with individual neural events are identical. However, no class of mental events is (types, such as headaches or pleasure ) with a class of neural events identical. The lack of identity of the classes prevented by Davidson, a reduction of the mental to the physical. Nevertheless, it is according to Davidson specify a relationship through the Supervenienzbegriff:

Davidson's use of the Supervenienzbegriffs had a very strong effect in the philosophy of mind. She promised an analysis of the psychophysical relations to imply without an implausible reductionism. The most influential interpretations of Supervenienzbegriffs has delivered Jaegwon Kim. Especially with Kim but the euphoria was beating fast into a skepticism regarding the Supervenienzbegriff. Kim argues that the supervenience could not explain the psychophysical conditions, but ask yourself for an explanation. Although one could provide the supervenience an answer to the question, what relation Mental and Physical stand. However, one must put up with the issue of what constitutes the Supervenienzverhältnis for some kind of relationship. Also, one could ask why the mental on the physical superveniere. Kim concludes that not solved with talk of supervenience, the mind-body problem, but was formulated: "Mind -body supervenience, THEREFORE, does not state a solution to the mind-body problem; rather it states the problem- Itself. "

Explanations of supervenience

The problem

In the philosophical debates is assumed usually assume that the claim of supervenience between A and B, a satisfactory information about the relationship between A and B can only be at first glance. Supervenienzbeziehungen seem to be no fundamental explanatory facts, but to demand even for an explanation. Here, the explanation for the psychophysical supervenience, depending on the metaphysical background belief differ. Physicalists, dualists and other Nichtphysikalisten must try to find an explanation for the psychophysical supervenience that is compatible with their metaphysics.

Physicalist strategies

From physicalists will usually try to explain the psychophysical supervenience reductive analysis: Can A reduce to B, then there is no longer a mystery why A supervenes on B. This context, one can easily make clear by examples. The property of a drop of water to be liquid, supervenes on the physical properties of the water droplet. You can not ( by freeze or evaporate ) change, without changing the physical structure of the water droplet that property. But this Supervenienzverhältnis is easy to explain. The properties of the water drop can be reduced to its physical properties. If the mental also be reduced to the physical, and this Supervenienzverhältnis could be easily explained: The mental property M would be about the physical properties P1 - Pn supervene because M nothing other than P1 - Pn would be.

Against reductionist theories of the mind is often argued that there are critical features of our consciousness, which made a reduction to physical structures impossible. A question that must face physicalist positions is whether there can be a physicalist explanation for the psychophysical supervenience, if the reductive efforts fail. The philosopher Terence Horgan has the concept of Superdupervenienz for Supervenienzbeziehungen marked that are acceptable in the context of a physicalist metaphysics. However, he remains skeptical with regard to the question of whether a satisfactory, nonreductive Superdupervenienzbeziehung can find.

As a way like an anti - realist interpretation appear, similar to the meta-ethical anti-realism (see section supervenience in ethics ). However, this position would be tantamount to a denial of the existence of the mental. Such eliminative materialism want to accept only a few philosophers.

Nichtphysikalistische strategies

Also for nichtphysikalistische positions is the psychophysical supervenience a challenge. If it is not simply mental states are physical states, the existence of psychophysical supervenience threatens to become incomprehensible. Therefore, a possible nichtphysikalistische strategy is to reject the supervenience.

Other Nichtphysikalisten accept the psychophysical supervenience and explain that mental states are linked by natural laws with physical states. According to such position the mental supervenes on the physical, since the mental is caused by the physical. This is also called " nomological " or " natural supervenience ". David Chalmers is currently the most well-known representative of such a position.

However, this position is also confronted with difficulties. One problem is about the fact that the postulated laws of nature can not be reducible to the fundamental physical laws, since they combine mental and physical facts. This means that you would have to expand the world to more fundamental laws of nature, a consequence which is criticized by many philosophers as implausible. There remains the open question of whether Nichtphysikalisten can offer a different interpretation of psychophysical supervenience.

Supervenience and externalism

For a long time it was assumed that the mental states of a person supervene on the neural states of the brain: No change of the mental state without a change in a brain state. This position must now be considered as controversial as Hilary Putnam and Tyler Burge claim to be able to show that the mental content also depends on the physical or even social environment of a person.

The classic argument for this position (also called externalism ), based on a thought experiment: Imagine our earth a Twin Earth before, similar to the Earth in almost every detail right down to the subatomic particles. There is only one difference: What on Earth is H2O, on Twin Earth another substance XYZ. Since the two worlds are otherwise identical, there is for each person on Earth an A twin B to twin earth, which is located in the exact same neural states. However, A and B do not have the same thoughts when they think " there is water." The idea of A, by referring to H2O, while the idea of B refers to XYZ. But if this is so, the mental can not supervene on the neural, as two people can be in the same neural state, without being located in the same mental state.

This problem was reacted in the philosophy of mind with the concept of global supervenience. With this thesis the Supervenienzbasis is extended, the mental is not supervene solely on the neural states, but generally over all physical states of the world. Such a position can be avoided with the thought experiment, because there really is a physical difference between Earth and Twin Earth. What on Earth is H2O, is on Twin Earth XYZ.

However, it was argued against global supervenience that it is not sufficient for a materialist position. Finally, the global supervenience is compatible with the following assumption: A twin solar system differs from our solar system physically only in that in the Saturn ring is missing an atom. Nevertheless, there are in the Twin Earth no mental states, people are all machines without consciousness. As the global supervenience seems to be compatible with such situations as opposed to materialism, is often assumed that global supervenience is not sufficient for a materialist theory.

The variety of Supervenienzbegriffe

In the philosophical debate various proposals for the correct definition of Supervenienzthese exist. The various formulations differ on the one hand, whether they are local or global Supervenienzthesen (see section supervenience and externalism ) on the other hand, they differ in the use of modal operators or possible worlds. These proposals, which are formulated in part to a very high technical level, vary so greatly, because the metaphysical background beliefs have a direct impact on the modal requirements for a correct Supervenienzdefinition. A physicalist who thinks that the mental is nothing but the physical, can not assume that the psychophysical supervenience is only a contingent fact.

De facto supervenience

The weakest formulation of Supervenienzthese comes from no modal operators: The property A supervenes on the property family B if there is no change of A, without a change of B. One can speak here with Ansgar Beckermann of " de facto supervenience ". For example, if each article having a heart, also has a kidney, so supervenes the property of having a heart, to the property of having a kidney. De facto supervenience in terms of the philosophy of mind, therefore, would mean simply: There is no change in the mental properties without changing the physical properties.

Most of the de facto supervenience is not considered sufficient for physicalism. If B over A only de facto supervenes, there is no necessary relation to here. And that means: Just as beings with hearts, but no kidney might develop, also beings could develop that will have us physically the same, but no consciousness. This must be a physicalist but refuse: If mental states are identical to physical states, then the physical states can not occur without the mental states. This is the logic of identity relations, as one can easily make it clear with an example: When Konrad Adenauer is the same as the first Chancellor of the Federal Republic of Germany, then it is simply not possible that Konrad Adenauer is at a point where not the first Chancellor of the Federal Republic of Germany is.

Weak and strong supervenience

In response to these problems is usually assumed that an element of necessity has to be brought into the supervenience. A first formulation may look like this: The characteristic feature of the Family A supervenes on B when there can be no change in A, without a change of B.

However, further differences here. Thus, it is asked whether the Supervenienzthese applies only for one or for each possible world. Applies first, we speak with Kim also of weak supervenience and distinguishes them from the strong supervenience, which also applies to all possible worlds. According to the weak Supervenienzthese there can not be two objects that are physically the same, but differ in a mental world. However, there could be an object in the world w1 that physically resembles an object in the world w2, but contains other mental properties. It is this case is excluded from the strong supervenience is therefore often argued that strong supervenience alone is adequate for physicalism.