Physicalism
Physicalism is in philosophy on the one hand a metaphysics critical program of logical empiricism, which aimed to express all empirical sciences in a unified physicalist language of science, in its ontological form of the metaphysical thesis that everything that exists physically is the other. Physically are all objects, properties, or events ( all entities ) that can be described in the theory of physics. This thesis of a complete physical structure of the world is controversial, but is represented by many present philosophers and natural scientists. Plays a special role of physicalism in the philosophy of mind, since the rejection of the idea of an immaterial consciousness is connected with it.
Although the term " physicalism " was first coined by the Vienna Circle, he is also used to refer to the so -intentioned position classical philosophers. Candidates are as representative of the thesis that there is nothing " spiritual " but " only material things ," that there is no eternal ideas, but only changing atoms, inter alia, On the other hand, speaks in today's systematic debates precisely because of physicalism rather than materialism, because not belong to many connotations of " materialistic " classical positions today, narrower concept of physicalism. Pre-modern representative of physicalism are therefore dealt with under materialism.
- 6.1 The concept of the physical
- 6.2 Qualia
- 6.3 Pluralistic arguments
Development
The term physicalism was particularly marked by Otto Neurath and Rudolf Carnap in a series of essays in the first half of the 20th century. Physicalism was part of an important critical metaphysics program ( unified science ) of logical empiricism, which had the goal to develop a common language in which the empirical content of all empirical sciences could be expressed. One motivation for this program is that the Logical empiricism adopted, so as to ensure the inter-subjectivity of Sciences and also to overcome the separation between humanities and natural sciences was.
Because of the represented by logical empiricism Methodological neutralism was connected with the adoption of a physicalist language no ontological statement; ontological questions were like all metaphysical statements are regarded as pseudo-problems, of which science should be largely free as possible. In principle, one could, for example, according to Carnap also use a phenomenalistic language as the basis of a unified science, as long as the language structure is specified exactly, so that translatability is given. The choice of a physicalist language had practical reasons, since in such a language intersubjectivity and especially Intersensualität are already provided. The choice of a physicalist language did not include the requirement of reducibility of the laws of all individual sciences to the physical laws, but only the expressibility of all statements of all the individual sciences in the physicalist language.
Physicalism and the diversity of philosophical positions
The metaphysics addresses the central problems in theoretical philosophy: the foundations ( conditions, causes or " first principles " ) and general structures ( regularities, principles ), and the meaning and purpose of the whole of reality or of being.
The ontology is also referred to as "general metaphysics." It is the philosophical basis for discipline that asks what exists. The central ontological question is: " What is it? " Then answered the physicalist that in reality exist only physical entities. "Entity " is a collective term for objects, properties, events etc.
With this answer, the physicalism turns out to be a variant of monism. Monists declare that only one type of entities exist. However, there is not only the physicalist monism, but also the idealist and the neutral monism. Idealistic monism agree to the physicalist to the fact that there is only one type of entities - but they state that only mental entities exist. That which appears as the physical world is in fact a product of the mind. Neutral monists maintain that there is only one kind of neutral entities. These entities should include physical and mental aspects, but his self neither physical nor mental.
The classic counterparty of physicalism is the dualism. Dualists, the thesis that there are two fundamentally different kinds of entities: physical and mental. In the history of philosophy, different variants of dualism have developed. While the classical dualism in the tradition of René Descartes by an interaction between the mind and the physical world (such as the brain ), so as deny other theories such mutual interference. The epiphenomenalism claims that the physical world acts on the mind, but not vice versa. The going back to Gottfried Wilhelm Leibniz psychophysical parallelism denies any causal interaction between the mental and the physical world.
A third class of ontological positions may be called " pluralism ". Pluralists explain that there are many different types of entities. Finally, there are positions that "what there is " reject the ontological question. They explain that this question has no general answer, but is dependent on how we describe the world. Such positions are often called " relativistic " or " pragmatist pluralism ". If the physicalist wants to make his position plausible, he has to face all the above alternatives ( idealistic and neutral monism, forms of dualism and pluralism ) argumentative.
The term " physicalism " is often used synonymously with the concept of materialism. In the current debates in the philosophy of science and philosophy of mind here is the term " physicalism " usual while philosophy in the context of historical depictions mostly from the " materialism " is talking about. However, there are some substantive differences: While the traditional materialism to the thesis is determined that all entities are composed of the smallest particles of matter, would not prescribe the physicalism of physics which entities ultimately postulated as fundamental. So physicalism would also be compatible with the result that the bestbestätigten physical theories require entities that can not be described as matter - such as gravitational forces.
Layer model of the world
Physicalists usually explain that the world consists only of elementary particles in an important sense. Although there are many other objects, such as trees, rocks or rabbits, but all these objects ultimately are nothing more than arrangements of elementary particles. This is the central idea of the " layered model of reality" ( " layered model of reality" ), in which each object is composed by objects of the next lower layer (see diagram).
A more precise formulation of the layer model provides the distinction between basic and complex physical entities. As a fundamental physical entities described by the microphysics, the smallest physical objects, processes, or properties apply. In most cases the basic physical entities are presented as the elementary particles and their properties. The complex physical entities, however, counts everything is composed of the basic physical entities or resulting from their composition. So the physicalist molecules, neurons, people, or planets are about as physical objects, since they are composed of elementary particles. As part of the layer model is the thesis of physicalism that everything follows from the composition of the basic physical entities. A dualist would, however, explain that the human mind simply does not arise from such a physical constellation.
It is often assumed that physicalism with the layer model of the world has a general reductionism result: If all objects are composed of elementary particles ( ie the objects of the last layer) and arise all the properties from the properties of elementary particles, so it should in principle be possible to explain everything at the level of microphysics and thus all true, due to scientific theories on the microphysics ( reduce).
However Physikalimus and such reductionism can not be equated with each other, since there are also attempts to formulate a nonreductive physicalism. Such theories assume that all objects are composed of basic physical particles but deny either that it is therefore possible to reduce all scientific theories or claim within the meaning of Emergenzhypothese the existence of irreducible properties.
Definition of physicalism
Since physicalism and reductionism can not be identified with each other, in the philosophy of an intense debate about the proper definition of physicalism is performed. Physicalism is indeed determined by the thesis that everything that exists is physically. However, it remains a problem as long as is not sufficiently clear how the mentioned thesis is to understand. So one can ask what it is that man or consciousness is physical, if you do not want to say at once that it can be reduced to the physical.
A popular proposal attempts to define physicalism by the concept of supervenience. The notion of supervenience describes the following relationship: A supervenes on B if and only if A can not be changed without that B is changed. An example is the ratio of physical properties and performing a work of art. Can not be the landscape, which is the image change, without at the same time to change the physical structure of the image. In this sense supervene the imaging capabilities of the image on the physical properties. David Lewis describes this relationship as follows:
Now it makes sense to define physicalism using the Supervenienzthese: All entities supervene on basic physical entities. Such a definition has, inter alia, the advantage over the reduction about neutral. Supervenienzverhältnisse are consistent with reductions, but not presuppose it.
On closer inspection, however, shows that supervenience alone is not sufficient for physicalism. Thus, there are dualistic positions that are compatible with the Supervenienzthese, eventually there may be immaterial entities, the only change if also changing something physical - more is not required by the Supervenienzthese. The epiphenomenalism and the psychophysical parallelism are to be regarded as about such dualisms. So the Supervenienzthese must be supplemented by an additional assumption to represent a definition of physicalism.
The linguist Noam Chomsky believes that since the revolutionary models of thinking of Isaac Newton, and René Descartes absent a satisfactory definition of physicalism. It is always unclear whether physicalism is meant by matter only, or even functions, structures and dispositions. Besides, it is far from clear where between these candidates a dividing line is to be set - this difficulty is revealed precisely in more complex phenomena such as language, consciousness, cybernetic systems and so on. But until this is the case, it has, according to Chomsky little sense to discuss the mind-body problem, or related topics.
Arguments for physicalism
Empirical evidence
Many scientists and philosophers see evidenced by the progress of the natural sciences, the truth of physicalism. You firstly have indicated that the (natural) sciences must fall back at any point of intangible causes. Where it was thought that only an immaterial cause could be explanation for a phenomenon, you 've finally found a physical cause. A typical example is the decline of physiological vitalism of the 18th and early 19th century, the vital postulated an intangible élan to explain the phenomenon of life. Eventually, however, this assumption has been superseded by a number of scientific developments as the first synthesis of an organic material by Friedrich Wöhler and the development of the theory of evolution in many ways.
In addition, physicalists suggest that the layer model of the world is empirically well confirmed. It now even can not find any objects in the world, which are not completely composed of smaller objects, and even the natural sciences showed how the properties of the objects from properties of more fundamental objects would result. These empirical results lead to the opinion of many physicalists by a conclusion as to the best explanation for physicalism.
Antiphysikalisten respond to this objection usually by trying to show that there are phenomena that stubbornly resisted the classification in the physicalist layer model. Thus, reference is made about the fact that numbers are real entities, which are not composed of more fundamental physical objects or it is argued that properties of consciousness as qualia or intentionality do not result from the biological properties of living beings. In addition, it is argued by Antiphysikalisten often that the physicalist wiedergäben the actual state of the science wrong. Thus, the current science of drawing by an increasing specialization in which more and more entities would postulated 'll always be shown without compromising how these entities would result from the more fundamental, ontological layer.
See the most physicalists in the empirical scientific results but also not a proof of physicalism, but rather an indication of the plausibility of their position that should a vote skeptical about antiphysikalistischen allegations. The classical arguments for physicalism are rather related to considerations of causality.
Causal arguments
Antiphysikalisten arguing for the existence of non-physical entities, such as from non-physical or mental states substances. Now it is argued by physicalists time and again that such positions could not explain the causal efficacy of the supposedly non-physical entities. Mental states have some obvious causal forces. Headache may be the cause of swallowing aspirin tablet be longing for a friend may result in a longer journey. Now physicalists argue that it also give a physical or biological cause for every action. For swallowing an aspirin tablet may vary in approximately the following reason: In the brain, neuronal processes were running from, which led to excitement redirects to the muscles, which in turn caused the swallowing of the tablet.
So it seems as if there were actions for the same two reasons: Firstly, the mental cause ( about headaches ) and secondly the physical cause. But now argue physicalists that such a general overdetermination and multiple causation by two or more causes is highly implausible. One can see this if you focus on real-world examples of overdetermination, such as a home that will set due to lightning and arson in flames. Of course, such cases may occur, but a general over-determination is ruled out. This is exactly what is required by dualists but if they assume that there is always a mental and a physical ( instrumental or secondary) cause of some actions. It is the argument for physicalism 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 over-determination. Premise 4: If premise 1-3 are true, then mental events are nothing more than physical events. Conclusion: Mental events are nothing more than physical events.
According to physicalists this argument shows not only that mental states are physical states. The argument 'll also be transferred to other entities on which a dualist could claim that they were not physically, such as aesthetic and ethical qualities. According to the physicalist thus show reflections on causality the truth of physicalism. Now, of course, different answers were developed by dualists.
While Epiphänomenalisten claim that mental states do have no effects, explain interactionist dualists with reference to the quantum physics that not every physical event has a physical cause, or argue for the possibility of a general over-determination or for the interaction of sub- causes. There the premises are 1-3 in doubt in the argument so.
Arguments against physicalism
The concept of the physical
A fundamental objection to physicalism is that the concept of the physical ultimately incomprehensible and therefore physicalism is meaningless. The problem was first formulated by Carl Gustav Hempel, which is why you also " Hempel's dilemma " is talking about. 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 is to count as a physical entity. Certainly, the physics, but the question remains, to which physics is to turn. If the current physics or a future idealized ' complete ' physics mean? If the current physics is meant as physicalism is probably wrong in the opinion of critics. Finally, I would highly implausible that the current physics would have identified all of the physical entities. But when one turns to a future ideal physics, so physicalism is trivial According to critics: An idealized - complete physics would necessarily fall back on all the basic entities, whatever they may be. And how could rule out there that are among the basic entities also Qualia, numbers, etc.? If you " physically " defined with the help of an ideally - complete physics, so even a classical dualist seems to be physicalist at the same time.
While some philosophers, such as David Lewis, explaining that the current physics in an important sense is already fully yet, try other philosophers to solve the dilemma by a third proposal. So suggests about Frank Cameron Jackson, " physically " to name all the entities that are used to describe the events of a certain size. The idea is that all of this is to be called "physical" what happens at the subatomic level, while macro properties such as the experience of pain a human being, should not be regarded as a fundamental physical entity. Such a separation could be made if we might only describe the subatomic entities as fundamental physical phenomena. This strategy may work well in mental states, however, has a problem about with the adoption of non-physical numbers. Numbers can not be ordered by spatial size and finally seem applicable at any level.
Qualia
The existence of qualia - subjective experience levels - is often considered to be the most serious problem of physicalism. To have seen the existence of qualia as sufficient reason for rejection of physicalism about David Chalmers and Frank Cameron Jackson. Roger Penrose also maintains equivalent. The basic idea is that the qualitative experience content, a property of many mental states is, but not reducible to the properties of physical states.
A well-known qualia -based argument against physicalism has been developed by Jackson: He designed a thought experiment of the super scientist Mary: Mary is a specialized color vision neuroscientist who is trapped in a black-and- white lab since birth and has never seen colors. She knows all the physical facts about seeing colors, but do not know how colors look. Jackson's argument against materialism is now quite short: Mary knows all the physical facts about seeing colors. Yet you do not know all the facts about seeing colors. So there are non- physical facts. So materialism is false. Are counter this argument, as against each qualia -based argument, various materialistic replicas have been put forward. Example, it was claimed that Mary gets to know no new facts, but only acquire a new skill. Also, it was claimed that Mary only get to know a fact already known in a new way.
The status of qualia -based arguments against physicalism is still highly controversial. Firstly, the concept of qualia itself is elusive and highly controversial. On the other hand also is not sure what is the status Qualia arguments. If they are metaphysical arguments that can enlighten us about the ontological status of the mental, or are they epistemological arguments that enlighten us especially about the limits of our knowledge? Had the latter been the case, the qualia problem would have no consequences in relation to the question of the truth of physicalism.
Pluralistic arguments
In addition to the problems described a much more fundamental criticism is voiced on physicalism occasionally. Representative of pluralistic and similar positions declare that the conception of physicalism is based on a completely wrong idea of the role of physics. They argue that the physics of a legitimate form of knowledge acquisition is true, but it must be made absolute in any way. Rather, the physical description of the world is one of many ways of describing, which in no way is " down" or " real " than the mental, aesthetic or economic description, however. One must accept that there is a plurality of perspectives and not one that only true description of the world, which is often assumed in the (micro) physics. There is thus a variety of levels, and the error of physicalism is the assumption that these levels would have to be traced back in a layered model to the physical plane.
Pluralistic positions are formulated from different metaphysical perspectives. An early proponent of pluralism was Alfred North Whitehead, who developed this idea in his major philosophical work process and reality. The philosopher of science John Dupré represents about a realistic pluralism, which implies a pluralistic ontology. Nelson Goodman argues, however, for a relativistic pluralism, which is not accompanied by a pluralistic ontology, but the abolition of ontological concepts. Hilary Putnam tried to formulate the internal realism an intermediate position in combination, in Germany represents Peter Bieri recently a comparable position.
The status of physicalism in contemporary philosophy
The physicalism is a position that was at times an almost unquestioned background assumption in analytical philosophy. This state of the (mostly combined with the reductionism ) physicalism is advised by two developments falter: For one, the metaphysical realist premises of classical physicalism were attacked from various sides. The most influential examples of this tendency are Goodman and the late Putnam. On the other hand in the modern debate the philosophy of mind has become increasingly clear that a reductive physicalist interpretation of consciousness leads to serious problems. These trends, however, have not often led back to a classic dualism, but to the development nichtreduktiver Physikalismen and pluralist positions. At the same time there are a number of philosophers who are of opinion that ultimately let see no alternative to a reductive physicalism, a well-known representatives of this position is about David Lewis. Thus, the output of the debate about physicalism remains open. To make matters worse, that the models of physicalism are often described according to classical physics and is by no means clear how a formulation based on quantum theory ultimately look like.