Physicalism (ontology)

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The Physicalism 's philosophy the metaphysical thesis that everything that exists, whether physical or that between the properties of all objects and real-world whose physical properties a supervenience relationship conquer. Physicalism is thus a monistic position that is in contrast to dualistic , pluralistic and idealistic positions.

There are different variants for the definition of the physical as well as for the explication of physicalism. According to a commonly used definition, any object, property or event (any entity ) is considered physical that can be described in the theories of physics .

Physicalist positions are represented by many contemporary philosophers and natural scientists, but physicalism is also the subject of controversial discussion.

Physicalism plays a special role in the philosophy of mind , since it is associated with the rejection of the idea of ​​an immaterial consciousness . Many proponents of modern physicalism advocate the thesis that the assumption that the spiritual is not determined by physical causes is wrong, since, according to scientific conception, there is insufficient evidence to doubt that mental phenomena are due to physical causes.

Physicalism is closely related to materialism . In today's systematic debates one speaks more of physicalism than of materialism, because many connotations to “materialistic” classical positions do not belong to today's, narrower concept of physicalism.

development

The term physicalism was coined in particular by Otto Neurath and Rudolf Carnap in a number of essays in the first half of the 20th century. Physicalism was part of an important metaphysics- critical program (unified science) of logical empiricism, which had the aim of developing a unified language in which the empirical content of all empirical sciences could be expressed. One motivation for this program was that Logical Empiricism adopted so as to ensure the intersubjectivity of the sciences and also to overcome the separation between the humanities and the natural sciences.

Because of the methodical neutralism advocated by Logical Empiricism, the assumption of a physicalistic language was not associated with an ontological statement; Like all metaphysical statements, ontological questions were viewed as pseudo-problems from which science must be freed as far as possible. In principle, according to Carnap z. B. also use a phenomenalistic language as the basis of a standardized science, as long as the language structure is precisely specified so that it can be translated. The choice of a physicalistic language had practical reasons, since such a language already presupposes intersubjectivity and, above all, intersensuality . The choice of a physicalistic language did not require that the laws of all individual sciences be reducible to physical laws, but only that all statements of all individual sciences can be expressed in physicalistic language.

Physicalism and the variety of philosophical positions

Representation of the different, metaphysical positions. Physicalism (top left) is a variant of monism.

The metaphysics addresses the central problems of theoretical philosophy: the foundations ( conditions , causes or "first principles") and common structures (legalities, principles ) as well as the meaning and purpose of the entire reality or all being .

The ontology is also referred to as "general metaphysics". It is the basic philosophical discipline that asks what exists. So the central ontological question is: “What is there?” To which the physicalist answers that in reality only physical entities exist. "Entity" is a collective term for objects, properties, events, etc.

With this answer, physicalism turns out to be a variant of monism . Monists declare that there is only one kind of entity. However, there is not only physicalistic monism, but also idealistic and neutral monism . Idealistic monists agree with physicalists that there is only one kind of entity - but they declare that only spiritual entities exist. What appears as the physical outside world is actually a product of the spirit . Neutral monists claim that there is only one kind of neutral entity. These entities are said to contain physical and mental aspects, but are themselves neither physical nor mental in nature.

The classic opponent of physicalism is dualism . Dualists argue that there are two fundamentally different kinds of entities: physical and mental. Various variants of dualism have developed in the history of philosophy. While classical dualism in the tradition of René Descartes assumes an interaction between the mind and the physical world (such as the brain ), other theories deny such mutual influence. The epiphenomenalism claims that the physical world acts on the mind, but not vice versa. The psychophysical parallelism , which goes back to Gottfried Wilhelm Leibniz , denies any causal interaction between the spiritual and the physical world.

A third class of ontological positions can be called “ pluralism ”. Pluralists explain that there are many different types of entities. Finally, there are positions that reject the ontological question “What is there?”. They explain that this question does not have a general answer, but depends on how we describe the world. Such positions are often called “relativistic” or “pragmatic pluralism”. If the physicalist wants to make his position plausible , he must argue against all of the above alternatives (idealistic and neutral monism, forms of dualism and pluralism).

The term "physicalism" is often used synonymously with the term materialism . In the current debates on the philosophy of science and the philosophy of mind , the term "physicalism" is common, while in connection with philosophical historical representations one usually speaks of "materialism". However, there are also certain differences in content: While traditional materialism is based on the thesis that all entities are composed of the smallest particles of matter, physicalism does not want to prescribe in physics which entities it ultimately postulates as fundamental. So physicalism would also be compatible with the result that the best-confirmed physical theories require entities that cannot be described as matter - such as gravitational forces .

Layer model of the world

Social groups
 
 
 
 
Creature
 
 
 
 
Cells
 
 
 
 
Molecules
 
 
 
 
Atoms
 
 
 
 
Elementary particles
Scheme according to Oppenheim and Putnam .

Physicalists usually explain that the world is made up of elementary particles in one important sense . There are also many other objects, such as trees, stones or rabbits, but ultimately all of these objects are nothing more than arrangements of elementary particles. This is the central idea of ​​the “layered model of reality”, in which each object is composed of objects from the next lower layer (see schematic illustration).

A more precise formulation of the layer model offers the distinction between basic and complex physical entities. The smallest physical objects, processes or properties described by microphysics are considered to be fundamental physical entities. Most often the basic physical entities are presented as the elementary particles and their properties. Complex physical entities, on the other hand, include everything that is composed of the basic physical entities or results from their composition. For the physicalist, for example, molecules , neurons , people or planets are considered physical objects because they are composed of elementary particles. In the context of the layer model, the thesis of physicalism is that everything arises from the composition of the basic physical entities. A dualist, on the other hand, would explain that human consciousness does not result from such a physical constellation.

It is often assumed that physicalism with the layer model of the world results in a general reductionism : If all objects are composed of elementary particles (i.e. the objects of the last layer) and all properties result from the properties of the elementary particles, it should in principle be possible to explain everything on the level of microphysics and thus all true, scientific theories to be reduced to microphysics.

However, physicalism and such a reductionism cannot be equated with one another, since there have also been attempts to formulate a non-reductive physicalism . Such theories assume that all objects are composed of basic physical particles, but either deny that all scientific theories can therefore also be reduced or, in the sense of the emergence hypothesis, claim the existence of irreducible properties .

Definition of physicalism

Since physicalism and reductionism cannot be identified with each other, there is an intense debate in philosophy about the correct definition of physicalism. Physicalism is determined by the thesis that everything that exists is physical. However, a problem remains as long as it is not sufficiently clear how the thesis mentioned is to be understood. For example, one can ask what it means that man or consciousness is physical, if one does not want to say at the same time that they can be reduced to the physical.

One popular proposal tries to define physicalism through the concept of supervenience . The concept of supervenience describes the following relationship: A supervises over B if and only if A cannot be changed without B being changed. An example is the relationship between the representational and physical properties of a work of art. You cannot change the landscape the picture represents without at the same time changing the physical structure of the picture. In this sense, the representational properties of the picture supervise the physical properties. 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.
An image from a dot matrix has global properties - it is symmetrical, it is jumbled, etc. - and yet all that is in the image is a point distribution at every point in the matrix. The global properties are nothing but patterns of the points. They supervise: no two images can differ in their global properties without differing somewhere in the point distribution.

Now it makes sense to define physicalism with the help of the supervenience thesis: All entities supervise over the basic physical entities. Such a definition has u. a. the advantage of being neutral towards the reduction issue. Supervenience relationships are compatible with reductions, but do not presuppose them.

On closer inspection, however, it becomes apparent that supervision alone is not sufficient for physicalism. So there are dualistic positions that are compatible with the supervenience thesis, after all there could be immaterial entities that only change if something physical also changes - nothing more is required by the supervenience thesis. The epiphenomenalism and psychophysical parallelism are about to be regarded as such dualisms. The supervenience thesis must therefore be supplemented by an additional assumption in order to represent a definition of physicalism.

The linguist Noam Chomsky takes the view that since the revolutionary thought models of Isaac Newton and René Descartes there has been no satisfactory definition of physicalism. It is always unclear whether physicalism only means matter or functions, structures and dispositions. Apart from that, it is by no means clear where a dividing line is to be set between the named candidates - this difficulty is particularly evident in more complex phenomena such as language , consciousness , cybernetic systems and so on. Until that happens, however, according to Chomsky, there is little point in discussing the mind-body problem or related issues.

Arguments for physicalism

Empirical evidence

Many scientists and philosophers see the truth of physicalism as evidenced by the advancement of science . On the one hand, they point out that the (natural) sciences do not have to fall back on immaterial causes at any point. Wherever one thought that only an immaterial cause could explain a phenomenon, one finally found a physical cause. A typical example is the decline of physiological vitalism in the 18th and early 19th centuries, which postulated an immaterial élan vital to explain the phenomenon of life . Eventually, however, a number of scientific developments such as the first synthesis of an organic material by Friedrich Wöhler and the development of the theory of evolution made this assumption superfluous in many ways.

In addition, physicalists point out that the layered model of the world has been well confirmed empirically . You cannot find any objects in the world that are not composed entirely of smaller objects, and the natural sciences have also shown how the properties of objects result from properties of the more fundamental objects. These empirical results, in the opinion of many physicalists, lead by a conclusion to the best explanation of physicalism.

Antiphysicalists usually respond to this objection by trying to show that there are phenomena that stubbornly oppose classification in the physicalist layer model. For example, it is pointed out that numbers are real entities that are not composed of more fundamental physical objects or it is argued that properties of consciousness such as qualia or intentionality do not result from the biological properties of living beings . In addition, antiphysicalists often argue that the physicalists misrepresent the actual state of the natural sciences. Current natural science is characterized by increasing specialization, in which more and more entities are postulated without always showing how these entities emerged from the more fundamental, ontological layer.

Most physicalists see in the empirical scientific results, however, not a proof of physicalism, but an indication of the plausibility of their position, which should make you skeptical of anti-physicalist claims. Rather, the classical arguments for physicalism relate to considerations of causality .

Causal arguments

Antiphysicalists argue for the existence of non-physical entities, such as non-physical mental states or substances. Now and again physicalists object that such positions cannot explain the causal effectiveness of the supposedly non-physical entities. Mental states would have obvious causal forces. Headache may be the cause of swallowing an aspirin tablet, longing for a friend may lead to a long journey. Now physicalists argue that there is a physical or biological cause for every action. For swallowing an aspirin tablet there are approximately the following reason: In the brain ran neural processes take place, leading to excitation redirects in the muscles, which in turn caused the swallowing the tablet.

So it seems that there are two causes for actions at the same time: on the one hand, the mental cause (such as a headache) and on the other hand, the physical cause. But now physicalists argue that such a general overdetermination or multiple causation through two or more causes is highly implausible. One can see this by focusing on real examples of overdetermination, such as a house that is set on fire by lightning and arson. Such cases can of course occur, but a general overdetermination can be ruled out. But this is exactly what dualists demand when they assume that there is always a mental and a physical (instrumental or secondary) cause for some actions . The argument for physicalism can be formulated as follows:

Premise 1: Mental states cause physical events.
Premise 2: Every physical event has a physical event as a sufficient cause.
Premise 3: There is no general overdetermination.
Premise 4: If Premises 1-3 are true, then mental events are nothing but physical events.
Conclusion: Mental events are nothing more than physical events.

According physicalists this argument is not only that mental states physical states are . The argument applies to other entities that a dualist might claim to be non-physical, such as aesthetic and ethical properties. Thus, in the physicalist's view, causal considerations reveal the truth of physicalism. Now, of course, different answers have been developed by dualists.

Concept of epiphenomenalism: the arrows symbolize causation

While epiphenomenalists claim that mental states have no effects at all, interactionist dualists with reference to quantum physics explain that not every physical event has a physical cause or argue for the possibility of a general overdetermination or for the interaction of partial causes. In the argument, therefore, premises 1–3 are called into question.

Arguments against physicalism

The concept of the physical

A fundamental objection to physicalism is that the concept of the physical is ultimately incomprehensible and that physicalism is therefore meaningless. The problem was first formulated by Carl Gustav Hempel , which is why one also speaks of “ Hempel's dilemma ”. A more recent, influential formulation is the essay There is no Question of Physicalism by Tim Crane and DH Mellor.

The dilemma arises from the question of who determines what should be considered a physical entity . Certainly the physics , but the question remains, which physics to turn to. Do you mean current physics or a future, idealized 'complete' physics? If current physics is meant, then the critics believe that physicalism is probably wrong. After all, it is highly implausible that current physics has already identified all physical entities. But if one turns to an ideal future physics, the critics believe that physicalism is trivial : idealized-complete physics would inevitably fall back on all fundamental entities, whatever their type. And how could one rule out that the basic entities also include qualia , numbers , etc.? If one defines “physical” with the help of an ideally complete physics, even a classical dualist seems to be able to be a physicalist at the same time.

While some philosophers, such as David Lewis , declare that current physics is already complete in an important sense, other philosophers try to resolve the dilemma with a third proposal. Frank Cameron Jackson , for example, suggests naming "physical" all the entities that are needed to describe events of a certain size. The idea is that "physical" should be called anything that happens at the subatomic level, while macro-properties, such as a person's experience of pain, should not be viewed as a basic physical entity. Such a separation could be made if only the subatomic entities were allowed to be called basic physical phenomena. This strategy may work well for mental states, but it has a problem with assuming non-physical numbers. After all, numbers cannot be ordered according to spatial size and seem applicable at every level.

Qualia

The existence of qualia - the subjective experience - is often held to be the most serious problem of physicalism. For example, David Chalmers and Frank Cameron Jackson saw the existence of qualia as a sufficient reason to reject physicalism. Even Roger Penrose claims equivalent. The basic idea is that the qualitative experience content is a property of many mental states, but cannot be traced back to the properties of physical states.

A very well-known qualifications-based argument against physicalism was developed by Jackson: He designs a thought experiment from the super scientist Mary : Mary is a neuroscientist specializing in color vision who has been trapped in a black and white laboratory since she was born and has never seen colors. She knows all the physical facts about seeing color, but she doesn't know what colors look like. Jackson's argument against physicalism is now quite brief: Mary knows all the physical facts about seeing colors. Still, she doesn't know all the facts about seeing colors. So there are facts that stand outside scientific conceptions, which therefore cannot adequately explain the phenomenon of color. So physicalism is wrong. As against any qualification-based argument, various physicalist replicas have been put forward against this argument. For example, it has been claimed that Mary does not learn new facts, but only acquires a new skill. It was also claimed that Mary was merely getting to know a known fact in a new way.

The status of qualification-based arguments against physicalism remains highly controversial. On the one hand, the concept of qualia itself is difficult to determine and very controversial. On the other hand, it is also not certain what status qualification arguments have. Are they metaphysical arguments that can enlighten us about the ontological status of the mental, or are they epistemological arguments that above all enlighten us about the limits of our knowledge? If the latter were the case, the quality problem would have no consequences with regard to the question of the truth of physicalism.

Pluralistic arguments

In addition to the problems described, a much more fundamental criticism of physicalism is occasionally expressed. Proponents of pluralistic and similar positions state that the conception of physicalism is based on a completely wrong idea of ​​the role of physics . They argue that while physics is a legitimate form of acquiring knowledge, it should in no way be made absolute. Rather, the physical description of the world is one of many ways of describing it, but it is in no way "deeper" or "more real" than the mental, aesthetic or economic description. One has to accept that there is a plurality of perspectives and not the one , only true description of the world that is often assumed in (micro) physics. So there is a multitude of levels, and the mistake of physicalism is the assumption that these levels must be traceable back to the physical level in a layer model.

Pluralistic positions are formulated from different metaphysical perspectives. An early representative of pluralism was Alfred North Whitehead , who developed this idea in his main philosophical work, Process and Reality . The scientific theorist John Dupré , for example, advocates a realistic pluralism that implies a pluralistic ontology . Nelson Goodman , on the other hand, argues for a relativistic pluralism that is not associated with a pluralistic ontology but with the abolition of ontological concepts. Hilary Putnam tries to formulate an intermediate position in combination with internal realism , in Germany Peter Bieri has recently taken a comparable position.

The status of physicalism in contemporary philosophy

Physicalism is a position that at times was an almost unquestioned background assumption in analytical philosophy . This status of physicalism (mostly combined with reductionism ) has been shaken by two developments: On the one hand, the metaphysically realistic premises of classical physicalism have been attacked from different sides . The most influential examples of this tendency are Goodman and the late Putnam. On the other hand, it has become increasingly clear in the modern debate on the philosophy of mind that a reductive physicalistic interpretation of consciousness leads to serious problems. However, these tendencies have often not led back to a classical dualism , but to the development of non-reductive physicalisms and pluralistic positions. At the same time, there are a number of philosophers who are of the opinion that ultimately no alternative to reductive physicalism can be found, a well-known representative of this position is David Lewis . The outcome of the debate about physicalism remains open. To make matters worse, the models of physicalism are often described according to Classical Physics and it is by no means clear what a formulation based on quantum theory will ultimately look like.

literature

Web links

Wiktionary: physicalism  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Premodern representatives of a physicalism are therefore dealt with in the article materialism .
  2. ^ Otto Neurath : Radical Physicalism and the Real World. In: Otto Neurath: Philosophical Papers. 1913-1946 (= Vienna Circle Collection. Vol. 16). Reidel, Dordrecht et al. 1983, ISBN 90-277-1483-5 , pp. 100-114, doi : 10.1007 / 978-94-009-6995-7_8 . Otto Neurath: Sociology in the Framework of Physicalism. In: Otto Neurath: Philosophical Papers. 1913-1946 (= Vienna Circle Collection. Vol. 16). Reidel, Dordrecht et al. 1983, ISBN 90-277-1483-5 , pp. 58-90, doi : 10.1007 / 978-94-009-6995-7_6 .
  3. ^ Willard V. Quine : On what there is . In: The Review of Metaphysics. Vol. 2, No. 5, 1948, ISSN  0034-6632 , pp. 21-38, JSTOR 20123117 .
  4. ↑ John Yolton: Thinking Matter. Materialism in Eighteenth-Century Britain. University of Minnesota Press, Minneapolis MN 1983, ISBN 0-8166-1160-2 .
  5. ^ Paul Oppenheim , Hilary Putnam : The Unity of Science as a Working Hypothesis. In: Herbert Feigl , Michael Scriven, Grover Maxwell (Eds.): Concepts, Theories, and the Mind-Body Problem (= Minnesota Studies in the Philosophy of Science. Vol. 2, ISSN  0076-9258 ). University of Minnesota Press, Minneapolis MN 1958, pp. 3-36, digitized version (PDF; 5.69 MB) .
  6. ↑ a b Jaegwon Kim : Supervenience and Mind. Selected Philosophical Essays. Cambridge University Press, Cambridge et al. 1993, ISBN 0-521-43996-5 , pp. 337-339.
  7. ↑ Jerry A. Fodor : Special Sciences (or: The disunity of Science as a Working Hypothesis). In: Synthesis. Vol. 28, No. 2, 1974, ISSN  0039-7857 , pp. 97-115, doi: 10.1007 / BF00485230 .
  8. ^ Charlie D. Broad : The Mind and its Place in Nature. Kegan Paul et al., London et al. 1925, (Reprint. (= Philosophy of Mind and Language. 3 = The International Library of Philosophy. 38). Routledge, London et al. 2000, ISBN 0-415-22552-3 ).
  9. ^ David K. Lewis : On the Plurality of Worlds. Blackwell, Oxford et al. 1986, ISBN 0-631-13993-1 .
  10. ^ Frank Cameron Jackson : From Metaphysics to Ethics. A Defense of Conceptual Analysis. Oxford University Press, Oxford 1998, ISBN 0-19-825061-4 .
  11. ^ Noam Chomsky : New Horizons in the Study of Language and Mind. Cambridge University Press, Cambridge et al. 2000, ISBN 0-521-65822-5 .
  12. ^ A b Frank Jackson : Epiphenomenal Qualia. In: The Philosophical Quarterly. Vol. 32, No. 127, 1982, ISSN  0031-8094 , pp. 127-136, doi: 10.2307 / 2960077 . Frank Jackson: What Mary didn't know. In: The Journal of Philosophy . Vol. 83, No. 5, 1986, pp. 291-295, doi: 10.2307 / 2026143 .
  13. ↑ Karl R. Popper , John C. Eccles : The I and his brain (= Piper. 1096). 8th edition, unabridged paperback edition. Piper, Munich et al. 2002, ISBN 3-492-21096-1 .
  14. ^ Ernest J. Lowe: Physical Closure and the Invisibility of Mental Causation. In: Sven Walter , Heinz-Dieter Heckmann (Eds.): Physicalism and Mental Causation. The Metaphysics of Mind and Action. Imprint Academic, Exeter et al. 2003, ISBN 0-907845-46-0 , pp. 137-155.
  15. ^ Carl Gustav Hempel : Reduction: Ontological and Linguistic Facets. In: Sidney Morgenbesser , Patrick Suppes , Morton White (Eds.): Philosophy, Science, and Method. Essays in Honor of Ernest Nagel. St. Martin's Press, New York NY 1969, pp. 179-199.
  16. ↑ Tim Crane, David H. Mellor: There is no Question of Physicalism. In: Min . Vol. 99, No. 394, 1990, pp. 185-206, doi: 10.1093 / mind / XCIX.394.185 , ( digital version (PDF; 1.3 MB) ).
  17. ↑ David Lewis : Reduction of Mind. In: Samuel Guttenplan (Ed.): A Companion to the Philosophy of Mind. Blackwell, Oxford et al. 1994, ISBN 0-631-17953-4 , pp. 412-421.
  18. ^ Frank Cameron Jackson: From Metaphysics to Ethics. Oxford University Press, Oxford 1998, ISBN 0-19-825061-4 , p. 6.
  19. ↑ “A scientific worldview can hardly seriously claim to be closed and complete if it leaves the problem of consciousness unexplained. Consciousness is part of our world, and a physical theory that leaves no place for it cannot be an adequate description of the world. ” - Roger Penrose : Shadow of Mind. Paths to a New Physics of Consciousness. Spectrum Akademischer Verlag, Heidelberg et al. 1995, ISBN 3-86025-260-7 , p. 8 ff .: Chapter 1.1: Spirit and natural science.
  20. ^ Joseph Levine : Materialism and Qualia. The Explanatory Gap. In: Pacific Philosophical Quarterly. Vol. 64, No. 4, 1983, ISSN  0279-0750 , pp. 354-361, ( digitized version (PDF; 577 kB) ).
  21. ^ John Dupré : The Disorder of Things. Metaphysical Foundations of the Disunity of Science. Harvard University Press, Cambridge MA et al. 1993, ISBN 0-674-21260-6 .
  22. ↑ Nelson Goodman : Ways of Worldmaking (= Hackett Classics. 51). Hackett, Indianapolis IN et al. 1978, ISBN 0-915144-52-2 (In German: Weisen der Welterzeugung. Translated by Max Looser. Suhrkamp, ​​Frankfurt am Main 1984, ISBN 3-518-57615-1 ).
  23. ^ Hilary Putnam : The Threefold Cord. Mind, Body, and World (= The John Dewey Essays in Philosophy. 5). Columbia University Press, New York NY et al. 1999, ISBN 0-231-10286-0 .
  24. ↑ Peter Bieri : Does the direction of the brain undermine the freedom of will? In: Christof Gestrich, Thomas Wabel (ed.): Free will or unfree will? Freedom of action and responsibility in the dialogue of the sciences (= Berliner theologische Zeitschrift. Supplement 2005). Wichern-Verlag, Berlin 2005, ISBN 3-88981-181-7 , pp. 20–31.
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