This does through up some disturbing possibilities however. Substance Dualism seems to imply that after the death of the physical brain, the non-physical mind will continue to ‘be’ or ‘live on’. Past philosophers, such as Descartes, have side stepped such questions of life when discussing the mind and brain –even though the question of what happens after death to our mind should be a pressing one for Substance Dualists. As disturbing as the possibility of eternal limbo of the mind is, this point is not a criticism as such the Substance Dualists point out; it does not disprove the theory but only introduces worrying questions associate with and of an ‘afterlife’.
Occasionalism, moreover, does not solve the problem of neural dependency. It seems odd, at best, that, as well as organising the world do that it appears that mental events cause physical ones, god would also have to manage things so that it appears that that physical events cause mental events. Take the example of drinking some beers, if one were to have too much alcohol it would cause one to become drunk. But as we know there is no interaction between the brain and mind according to Occasionalism, so that this means that god has to mess with our minds in order to produce the conscious experience of feeling ‘drunk’.
Solipsism, the problem of other minds, is a philosophical problem that is particularly difficult for Substance Dualists. As Descartes shows with his Cogito, we are all thinkers, or at least I know I am a thinker, since that “I cannot doubt I can doubt,” but how does one know that others have conscious minds too? We may not be able to doubt our consciousness, but we can everyone else’s; even extending so far as being sceptical of everything outside of your own direct consciousness – including your own body.
Such problems as mind body interaction, neural dependency, and Solipsism, result in the invertible consequence of substance dualism being thrown onto the philosophical scrap heap: a failed theory in need of replacing. The sensible conclusion would be to state that all mental processes are very much reliant on the physical brain.
The Identity Theory states, conversely, that all mental states (thoughts, sensations, reasoning: the ‘internal content’ of the mind) are all fully explicable and identifiable in terms of the physical properties of the brain. The ‘mind’ then, is fully reducible to the physical brain. The question of other minds seems to be solved since anything with a brain must therefore also have a mind.
The Type-Type theory used by some Identity Theorists is a way of explaining how the conscious feeling of something is just another way of experiencing the physical happenings going on the brain. So if someone were to say that they were in pain, this is just another way of describing a brain state in which C-fibres were firing. This solves the problem of mind body interaction and neural dependency, since mind states are brain states. Pain therefore exists if, and only if, C-fibres in the central nervous system are firing in the person in question.
Thus, in theory, if one were to know everything about the neurological goings on inside someone’s brain, you would gain third person experience to whatever that person was thinking/feeling about. This leads us to the conclusion that there is no privacy of the mental, as we can categorically find out whether other people/organisms have mental experiences that are similar to mine – solving the Epistemological problem of mind.
Be that as it may, a critic of this theory may well point out that neurons not seem to be ‘about’ anything. There are certain qualitative that are unique to the person experiencing them. The problem of Qualia is such an example. Whenever I am in pain, or experiencing that ‘reddish’ kind of feeling when I look at a ripe tomato, there appears to be a phenomenological quality that is not possible to gain from a third person perspective. Take the example of Mary the neuroscientist, she has been brought up in a world without colour – only ever experiencing black and white - but at the same time she is an expert in neuroscience and knows everything there is to know about the physical processes and mechanics going on in the brain when it is experiencing colour. Then one day she is released and cries out “so that’s what red looks like.” The point being made here is that qualitative experiences are, contrary to Identity Theory thinking, private to the individual. If one were to try to explain the taste of a food, say marmite, they could outline which of the five main tongue senses it invoked. But, it can never be experienced ‘in that way’ by anyone apart from you.
A response to this criticism is that understanding red, or marmite, from a third person perspective and actually experiencing it are two different presentations of the fact. Take the three simple forms of all physical properties: solid, liquid and gas. When a chemical compound changes between these different forms, it always keeps (if unmolested by outside forces) its same chemical compound. Taking a non-scientific example, The Mysterious Case of Dr Jekyll and Mr Hyde has, as the name of the novel suggests, two different main characters. Nevertheless on closer inspection it is revealed to the audience that these two men are in fact the same person – Dr Jekyll is Mr Hyde and vice versa – only they are presented in two different ways.
Finally, the last obstacle to be faced by Identity Theorists is that of the Ontological: Do other people have minds at all? One could conceive, perhaps, of a neurological zombie: a thing that has a synthetic human brain and is thus indistinguishable from a human. One could question the integrity of such an argument – is it even possible to have such a thing? But, for the sake of argument, we shall brush past this criticism. The Substance Dualists may well shout with glee, “look it has a brain, but it must have no mind since it’s synthetic!” Nonetheless, the Identity Theorists are not flustered; “if it has a brain, it must therefore have a mind” they would argue.
Overall, as we have seen, Substance Dualilism has been discredited as a theory – failing at such hurdles as mind body interaction and neural dependency. Furthermore, attempts to prove that this is privacy of the mental via the epistemological and ontological problems, such as Qualia and the neurological zombie, have also been fruitless. As for solipsism, the Identity Theory states that since the mind is fully reducible to the brain, anything that has a brain must therefore also have a mind. This leads us to the conclusion that there is, at least in theory at the moment, no privacy of the mental: in the future though, will be technology able to ‘read’ minds.
by
thomasrobinson01hotmailcouk (student)
