FUNCTIONALISM

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INTRODUCTION

Most Popular and well known theory of mind.

This doctrine is rooted in Aristotle's conception of the soul, and in Hobbes's conception of the mind as a “calculating machine”.

Become fully articulated only in the last third of the 20th century.

Focuses exclusively on functionalism as a philosophical thesis about the nature of mental states.

 

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ANTECEDENTS OF FUNCTIONALISM

Early Antecedents- an earliest ancestor of functionalism is Aristotle's theory of the soul (350 BC). In contrast to Plato's claim, that the soul can exist apart from the body. Aristotle argues, the soul is inseparable from the body, and comprises whichever capacities are required for a body to live, perceive, reason, and act.

Second, relatively early, ancestor of contemporary functionalism is Hobbes's (1651) account of reasoning as a kind of computation that proceeds by mechanistic principles comparable to the rules of arithmetic. Reasoning, he argues, is “nothing but reckoning, that is adding and subtracting, of the consequences of general names agreed upon for the marking and signifying of our thoughts.” 

It speculates, thinking may be nothing more than rule-governed computation that can be carried out by creatures of various physical types.

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CONTI…

Thinking Machines and the “Turing Test”

Behaviorism - Other important recent antecedents of functionalism are the behaviorist theories that emerged in the early-to-mid twentieth century.

These include both the empirical psychological theories and the “logical” or “analytical” behaviorism of philosophers .

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VARIETIES OF FUNCTIONALISM

Machine State Functionalism -According to Putnam's machine state functionalism , any creature with a mind can be regarded as a Turing machine (an idealized finite state digital computer), whose operation can be fully specified by a set of instructions (a “machine table” or program) each having the form:

If the machine is in state Si, and receives input Ij, it will go into state Sk and produce output Ol (for a finite number of states, inputs and outputs).

That’s why, Turing machines provided a fruitful model for early functionalist theories.

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CONTI…

Psycho-Functionalism - It derives primarily from reflection upon the goals and methodology of “cognitive” psychological theories. Psycho-functionalism, therefore, can be seen as straightforwardly adopting the methodology of cognitive psychology in its characterization of mental states and processes as entities defined by their role in a cognitive psychological theory.

Analytic Functionalism -The goal of analytic functionalism is to provide “topic-neutral” translations, or analysis of our ordinary mental state terms or concepts.

Basic idea of analytic functionalism is that theoretical terms are implicitly defined by the theories in whose formulation they occur and not by intrinsic properties of the phonemes they comprise. In the case of ordinary language terms, such as "belief", "desire", or "hunger“.

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WHAT IS FUNCTIONALISM

Theory in philosophy developed as an answer to the mind-body problem because of objections to both identity theory and logical behaviorism.

Theory about the nature of mental states.

According to it , “Mental states are identified by what they do rather than by what they are made of.”

Therefore, Core idea behind functionalism is that “mental states are more like mouse traps than they are like diamonds.”

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FUNCTIONALIST PERSPECTIVE

Functionalism tries to move beyond both Behaviorism and Identity Theory, by taking elements from both.

Contrasted with identity theory, functionalism introduces the idea that mental states are multiply realized.

That is,

“Brain states are not mental states”. Identity Theory supposes that brain states are identical to mental states. However, there are problems with this. If I say, "I am in pain" it is not the same as saying, "The C-fibres in my brain are firing".

Functionalism offers an account of mental states that is compatible with materialism, without limiting the class of those with minds to creatures with brains like ours.

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CONTI…

Behaviourism cannot account for mental states. Contrasted with behaviorism, functionalism retains the traditional idea that mental states are internal states of thinking creatures.

Different behaviors can result from the same stimulus. In other words, there is no one response that can be linked to the same stimulus. For example- Response for a doorbell.

Different stimuli can produce the same response. In other

words, there is no certain, one-to-one relationship between a stimulus and a response. For Example-One may laugh by seeing a photo & one may just laugh at seeing a parrot.

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HOW IS FUNCTIONALISM DIFFERENT?

Functionalism agrees that brain states are responsible for mental states, but disagrees that they are identical with them.

It argues that neurological states or brain activity help to realise mental states, which then lead to behavior.

It solves the main problems with the other two theories by proposing that brain states are "low level" activities that help realise "high level" mental states.

For Example- In case of computers, , the software(High Level) is a function of the hardware(Low Level).

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THEORY’S THAT SUPPORT FUNCTIONALISM

Turing Test.

Putnam's Twin Earth thought experiment.

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TURING TEST (1950)

English mathematician ,A.M. Turing proposed that the question, “Can machines think?” can be replaced by the question, “Is it theoretically possible for a finite state digital computer, provided with a large but finite table of instructions, or program, to provide responses to questions that would fool an unknowing interrogator into thinking it is a human being?”

Now, this question is most often expressed as “Is it theoretically possible for a finite state digital computer (appropriately programmed) to pass the Turing Test?”.

Turing identifies thoughts with states of a system, defined solely by their roles in producing further internal states and verbal outputs. Indeed, Turing's work was explicitly invoked by many theorists during the beginning stages of 20th century functionalism, and was the avowed inspiration for a class of theories, the “machine state” theories most firmly associated with Hilary Putnam (1960, 1967) that had an important role in the early development of the doctrine.

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CONTI…

Functionalism's explanation of consciousness, or the mental, is best understood when , the analogy is made to a "machine" that is capable in principle, of computing any given algorithm (i.e. as having the capabilites of a Turing machine).

This machine would involve:

- Data input (the senses in humans).

- Data output (both behavior and memory).

- Functional states (mental states).

- The ability to move from one functional state into another.

- The definition of functional states with reference to the part

they play in the operation of the entire entity.

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By Hilary Putnam. Imagine a Twin Earth which is identical to Earth in every way but

one: water is not H20, it's a substance XYZ. It is absolutely critical, however, to note that XYZ on Twin Earth is still called 'H20' even though it is a different substance (i.e. the one we call 'XYZ' on Earth).

Since these worlds are identical in every way but one, you and your Twin Earth Doppelganger see exactly the same things, meet exactly the same people, have exactly the same jobs, and behave exactly the same way. In other words, you share the same inputs, outputs, and relations between inputs and outputs. But there's one crucial difference. You know that water is H20. Your Doppelganger knows that water is XYZ. Therefore, you differ in mental states though the causal properties that define your mental states are identical.

PUTNAM'S TWIN EARTH THOUGHT EXPERIMENT

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OBJECTIONS FOR FUNCTIONALISM

Motive-Two objections to functionalism that aim to show that the theory is untenable. Both objections assume that mental states are, multiply realizable.

The objections try to show that because of its commitment to multiple realization, functionalism must accept certain unpalatable consequences. The conclusion of each argument is that functionalism is false.

The two objections are -

a. John Searle’s Chinese Room

b. Zombies

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JOHN SEARLE’S CHINESE ROOM

Famous objection to functionalism.

Its purpose is to refute strong AI and functionalism.

Searle’s Chinese Room objection focuses on contentful

mental states like belief and understanding.

Searle’s “Chinese Room Argument is aimed at computational versions of functionalism, particularly those that specify the relevant functions in terms of inputs and outputs without fixing the internal organization of the processes.

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CONTI..

Method- Searle imagines that someone who does not understand Chinese is placed in a room with an "In" hatch and an "Out" hatch. Through one hatch come Chinese symbols, which the person responds to by arranging other Chinese symbols according to rules laid down in a book and sending them out through the other hatch.

Searle considers this a certain view of artificial intelligence. But would the person in the room really be said to understand Chinese?

Searle thinks no and therefore argues that “no view of artificial intelligence could ever result in a truly conscious being (in the human sense) because all that is ever happening is rule-based activity (which is not how humans work)”.

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CONCLUSIONS

The version of functionalism represented by Strong AI must be false. Having the right functions, is not sufficient for having mental states.

Since functionalism holds that being is doing. That is, two systems that are functionally the same, should also be the same with respect to their mental states. But if Searle is correct, the system including the books and himself is functionally but not psychologically identical to a person who understands Chinese. And if so, this is incompatible with functionalism.

Searle has shown that input-output functionalism can’t be the whole story about mental states.

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ZOMBIES

It concentrates on the idea that according to such a view of the mind, it is possible to imagine zombie-like, non-conscious creatures that do not possess “qualia” (the qualitative aspect of mind – what it is like to be you) . Such creatures, whilst fitting the Functionalist criteria for possessing a mind, could not – non-functionalists argue – be said to be human in the full sense (thereby implying that the Functionalist view is inadequate).

Therefore, the non-functionalist wants to argue that qualia are necessary in addition to any functionalist explanation in order to account for minds. Because, our subjective experiences are the most real for us.

Another possible problem consists in Functionalism’s definition of what a mind consists of. Since, according to Functionalism, all that is needed to define a mind is that certain functional roles are fulfilled by certain parts, there is no need for the mind to be made out of anything in particular.

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FUTURE OF FUNCTIONALISM

In the last part of the 20th century, functionalism stood as the dominant theory of mental states.

The sophistication of functionalist theories has increased since their introduction, but so has the objections to it, especially to functionalist accounts of mental causation , introspective knowledge , and the qualitative character of experiential states.

For those unconvinced of the plausibility of dualism, however, and unwilling to restrict mental states to creatures physically like ourselves, the initial attractions of functionalism remain.

The primary challenge for future functionalists, therefore, will be to meet these objections to the doctrine, either by articulating a functionalist theory in increasingly convincing detail, or by showing how the intuitions that fuel these objections can be explained away.

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RECENT ADVANCEMENTS

Functionalism remains the most widely accepted theory of the nature of mental states among contemporary theorists. Nevertheless, recently, perhaps in view of the difficulties of working out the details of functionalist theories, some philosophers have been inclined to offer supervenience theories of mental states as alternatives to functionalism.

But as Jaegwon Kim correctly pointed out, supervenience simply allows us to pose the question about the nature of mental states, it is not an answer. The question is: Why do mental states supervene on the physical states of the creatures that have them, or at least of the world altogether? Functionalism provides one possible answer: Mental states supervene on physical states because mental states are functional states, i.e., they are realized by physical states. Much remains to be said about such a theory, and to many philosophers the arguments for it do not seems as decisive in 2008 as they did in 1968. But there is no denying that it is an intriguing and potentially powerful theory.

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SUMMARY

Functionalism attempts to overcome some of the problems with identity theory and behaviorism to forge them into a new, materialist view of the mind.

In doing this, it uses a computer model which describes the mind as a “multiply realisable” total functional system. In other words, it is like the calculations and rules that make up a software program that can be run on any machine.

In this way, it both lends itself to arguments for AI (Artificial Intelligence) and provokes counter-arguments from those opposed to the possibility of AI (and therefore using the computer model as a description of the mind).

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