Functionalism (philosophy of mind)

Functionalism is one of the classic positions of the philosophy of mind. Their central thesis is that mental states are functional states.

Functionalism and Functional states

The core theme of the philosophy of mind is the mind-body problem. It arises from the question of the nature of mental states. Let yourself be in a materialistic world view or integrate only be explained by an immaterial spirit? Functionalism argues that it is functional states in mental states. Since functional states can be realized by physical systems, functionalism is generally regarded as a materialist position. It applies, however, to remember that functionalism initially occupies an ontologically neutral position: It speaks in principle nothing to prevent intangible systems - if there are such because - can be functionally characterized.

A functional state is defined in that it responds to a particular input to a particular output, and is excreted in a different functional state. One can discuss the concept of a functional condition using simple examples. From the philosopher Ned Block is about the example of a Coke machine: Given a machine that outputs a can of Coke after a throw of one euro. He accepts 1 - euro and 50 - cent pieces. To be functional, the machine must have different internal states. There must be a state in which the machine calls for a Euro to output a can, but it must also be a state in which the machine asks only 50 cents. One can illustrate the functional architecture of such machines by following simple table:

The machine has two different states, each react to two different inputs and can either remain in the same state or change to the other state. By this table, the functional states are defined. The point of such a functional characterization of a system now is that it is independent of the actual physical implementation of the system: It is about completely irrelevant whether the machine is made of plastic or steel.

The thesis of functionalism is now, that mental states can be defined in such a manner. Who is in a mental state ( for example, has a headache or thinks that today is Monday ), will respond to a particular input in a certain way and go in a different mental ( functional ) state. It all functionalists is clear that the description of the mental inner life must be much more complex than the description of a Coke machine. The point of this thesis is now that even away its mental states is independent of the physical realization with her. This could have mental states a computer or a robot, if he only realized the same functional status as a living being with consciousness.

The development of functionalism

The development of functionalism is closely connected with the problems of identity theory and the emergence of cognitive science. The identity theory was formulated in the 50s by John Smart and Ullin Place. It says that a mental state - such as headaches - with a particular neural state is identical.

Against this theory was, however, objected that it is empirically plausible that different entities in the same mental state can be, even if they are located in different neural states. It is likely, for example, that people and cats can have a headache. However, the brains are so different that it is implausible that they are in the same neural state. This is known in the philosophy of multiple realization. So you can not identify headaches generally with a specific neural state.

In addition to that in the fifties and sixties, the Artificial Intelligence (AI) and cognitive science emerged. The identity theory, it seemed, however, be excluded a priori that a robot could ever have consciousness, as he has no neural states.

In this situation the first time in 1960, formulated by Hilary Putnam functionalism appeared to be a clear improvement, as it describes functional states as independent of their concrete realization. So this functionalism has no problem with the multiple realization. He also does not rule out that systems can have mental states without biological brains. Even a Turing machine can theoretically achieve any desired functional state. These advantages led to functionalism to the common philosophy of artificial intelligence and cognitive science was. Due to the problems of functionalism that status is now called into question again.

Objections to functionalism

Despite its popularity of functionalism with weighty objections is facing.

Strange realizations

One of the classic objections to functionalism comes from the philosopher Ned Block. Block, the fact is to use that functional states in different systems can be realized. By means of a thought experiment try block to imagine a situation in which a system has the same functional architecture as a confident person, but no consciousness. If such a system could exist, then functional states can not be identical to mental states.

In the article " Troubles with Functionalism " introduces himself to block, that the Chinese government carried out a large-scale Funktionalismusexperiment. Each of the 1.3 billion Chinese people get a radio device with which he can contact other Chinese. The whole thing is coordinated by huge spotlights that project commands to the cloud cover. Such a system of people, radios and headlights could, so block, realize, at least for a short time each functional state that a person can realize. Yet it would be completely absurd to assume, according to Block, that such a system would have mental states. Therefore, functional states and mental states can not be identical. Block objection has become known as the objection of " strange realizations ."

Qualia

Functionalism also has to struggle with a problem that even many proponents - is believed to be unresolved - such as Jerry Fodor. If all mental states are functional states, as well as experiences such as pain, functional status need to be. Now it is certainly plausible that some pain is to describe functional: Who 's in pain, will usually tend to have a certain behavior - for example, lie in bed, but not dance - and also certain other mental states - about sadness, but not euphoria.

The crucial question is whether the functional description of the phenomenon of pain is already fully covered. And here raises serious doubts: Certainly, the functional characterization is an important part of the pain, but another element seems much more important: the experience of pain. However, the fact that we experience pain - pain so have qualia - seems to be taken into account by the functional description in any way. The accusation of the functionalism is therefore that he could not explain the Qualia or experience levels of mental states. It is therefore not clear whether a certain functional architecture is sufficient for experience. Therefore, it seems implausible to equate mental states with functional states. To illustrate think of a computer that has the same functional structure as a man with severe pain. Experience the computer actually pain?

Daniel Dennett claims now to have solved the qualia problem.

Externalism

Hilary Putnam, who was one of the founders of functionalism is now considered one of the most influential critics of this position. His best-known anti- functionalism arguments related to the externalist slogan: " Thoughts are not in the head ". Putnam tries to show that an idea is not an internal state, but is co-constituted by the community and the environment. However, since functional states are internal states is not possible an identification of mental and functional states. Putnam offers two arguments:

1) elm and beech: Putnam explains that he only knew about elm and beech, respectively, that there were trees. This means that the internal functional structure of these thoughts could be the same. Nevertheless, the thought " The elm is a tree " and " The beech is a tree " different because they refer to different things. But if thought to be different, although the functional structure is the same, then thoughts and functional states can not be identical.

2) Twin Earth: Putnam's second argument is based on a thought experiment: He imagines a planet that resembles our world in detail. There is only one difference: What is our H20 is on Twin Earth, a substance XYZ, but the same macro properties as water. So it is liquid, transparent, odorless, etc. Now, a person A has on the earth the same functional structure as his twin B to twin earth. Nevertheless, they have some different thoughts: A refers to the idea " water is liquid " on the substance H20, B with the same thoughts on XYZ. The result: Since individuals with the same functional organization may have different thoughts, thoughts are not identical with functional states.

Variants of functionalism

Within the functionalist distinction is made between two different currents, depending on whether the mental states by folk psychology, or the science of psychology can be determined. The first alternative, according to our everyday terms such as " pain ", " joy " or " anger " functionally determines. This position is also known as common-sense functionalism. The second, according to position it is about conditions that have been determined in psychological research. Accordingly, one speaks of " Psychofunktionalismus ".

The common-sense functionalism has been joined by David Lewis with elements of identity theory: While the folk psychological terms alone were functionally characterized, the mental states of an individual are, in turn, with their neural states identical and could be reduced to it.