Critically Assess Some of the Varieties of Functionalist Philosophy of Mind

Critically assess some of the varieties of functionalist philosophy of mind.

There are various branches in the philosophy of mind, one of which is functionalism. Functionalism is a doctrine that posits that the causes of a mental state of a particular type does not necessarily depend on its internal constitution, but instead solely on the role it plays in the system it is a part of, or in other words, the way it functions. According to Functionalism, these mental states are caused by relations to sensory inputs, relations to other mental states, and behaviour. In brief, it can be said that, according to functionalism, mental states are identified by what they do rather than what they are made of. A more detailed overview of functionalism will follow, but, for the mean time, let us focus on how this relatively new theory came to be so popular amongst philosophers of mind.

The functionalist conception is probably the most widely held theory amongst philosophers in the field of philosophy of mind today. However, despite being almost certainly the most popular, this does not mean it is without its flaws. In fact, countless arguments have been made about functionalism, yet, without a superior, infallible opposing theory, functionalism is, despite these flaws, is the theory held by most. As Heil puts it "In the absence of clear competitors, many theorists have opted to stick with functionalism despite what they admit are gaps and deficiencies, at least until something better emerges. In this way, functionalism wins by default." (Heil, 2004, p.90)

Breaking away from antiquated Cartesian dualism and other such outdated theories, functionalism is said to have been developed specifically as an alternative to both the identity theory of mind and behaviourism. In fact, it can be said that the main arguments for functionalism depend on showing that it is superior to these primary competitors. In contrast to identity theory, functionalism contends that mental states can be multiply realized and in contrast with behaviourism, functionalism keeps the traditional idea that mental states are internal states of thinking creatures. It seems necessary then to first give a brief account of each of these prior theories of mind to understand the reasons why functionalism surpassed its competing theories in order to become so widely held.

The identity theory of mind first came to prominence in the 1950s and 1960s through the work of a number of psychologists, many of whom proposed their own versions of the theory. What held all the various theories together was the belief that when talking about mental states and processes, these mental states and processes are identical to states and processes of the brain. Previous theories had contended that these states and processes were merely correlated, so, it can be said then, that the identity theory of mind holds that when taking for example, an experience of pain, these experiences are brain processes, and are not merely correlated with brain processes. This however does not necessarily mean that the mind is identical to the brain. What divided philosophers into camps over the issue of identity theory, was the claim of the Australian philosopher David Armstrong that all mental states are literally identical with physical states.

Other philosophies contend that even though brain processes are related to experiences, these experiences are rooted in non-physical properties, something which is often referred to as 'qualia'. Qualia is a term used in various branches of philosophy to describe to subjective conscious experiences, indeed, the term itself is derived from the Latin word for "what kind". Identity theory, through its very nature, denies the existence of so called 'qualia', that is to say it denies the existence or irreducible, non-physical properties.

Where identity theory is seen to fall down is on an issue of which functionalism takes a differing view. This issue is the one of multiple realisability. This argument against identity theory was originally put forward by Hilary Putnam in his paper "The Nature of Mental States" (1967). He contends that firstly, there is a unique chemical state of the brain for each and every mental state which occurs. As such, something can only be in a given mental state if such a chemical state of the brain occurs. Added to this, Putnam posits that it is possible that other life-forms can achieve the same mental state, without having the exact same chemical brain state. This simple and logical argument is seen to defeat identity theory as a theory of mind and diminished its role in modern debates concerning the relationship between mind and body. Markus Eronen sums up how Putnam's argument was seen to defeat the identity theory. "Putnam took as an example "pain", or the state of being in pain, and argued that the identity theorist would have to claim that there is a physical-chemical state such that any organism...is in pain if and only if its brain is in that physical-chemical state. He further argued that if we can find even one psychological state that can be found in different species, but whose physical-chemical "realizer" is different in these species, the identity theory has collapsed." (Eronen, 2012, p.68) We will look at the issue of multiple realisability in more detail but for the meantime, let us look at the other major theory functionalism had to contend with.

The field of philosophy of mind was dominated by behaviourism in the first half of the 20th century. Behaviourism can be characterised by the thinking that mental states are not interior states; rather, they are descriptions of behaviour or dispositions to behave in certain ways. Put simply, behaviourists believe that behaviour can be explained without making reference to internal mental events or processes and additionally they would reject the study of introspection as a valid means of experimental investigation. Instead, they believe that external sources direct behaviour. Due to this, behaviourists would state that psychology, rather than being the science of the mind, is instead the science of behaviour. Functionalism disputes the validity of behaviourism because it acknowledges the existence of internal mental states. Where behaviourists would claim that the mental states a thinking creature has would depend entirely on that creatures behaviours, functionalists refute this and contend that distinct mental states could result in the same behaviours. Due to the fact that, according to the functionalist doctrine, separate mental states can result in the same behaviours, functionalists claim to have surpassed behaviourism.

Having discussed the precursory doctrines that in some ways instigated the coming about of functionalism, let us now scrutinise the theory in