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Oct 27, 2014



Functionalism and Its aspects



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.



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.




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 .



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).

Thats why, Turing machines provided a fruitful model for early functionalist theories.



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.




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.



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.



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.



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).



Turing Test.Putnam's Twin Earth thought experiment.


TURING TEST (1950)2/21/2011

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.



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.



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.




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 Searles Chinese Room b. Zombies



Famous objection to functionalism.

Its purpose is to refute strong AI and functionalism.Searles Chinese Room objection focuses on contentful mental states like belief and understanding.

Searles 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.



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).



The version of functionalism repres