Mind, Language and Reality
Concerning “The nature of mental states”
In “Mind, Language and Reality” Hilary Putnam discusses the question what mental states really are. He wrote at a time where already two hypotheses existed. One of them contends that mental states are brain states (in a neurophysiological sense) and the other one claims that mental processes are nothing but bodily behaviour. Putnam himself did not see anything convincing neither in the first theory, the brain-state hypothesis or Identity theory, nor in the second theory, the Behaviourism. He introduces another possible hypothesis, which I will present in the following essay. However, before I do so, I give an overview of possible problems that occur to Putnam according to the Identity theory.
First of all, he remarks that brain-state theorists have to explain and to prove many things in their claim, that being in a mental state is the same as being in a certain brain state and that there are no other feasible states. They say for example, if you feel pain, you are in the mental state of feeling pain, which is nothing but a special brain state and therefore a physical-chemical state of our brain. According to Putnam, this hypothesis can only be maintained, if the identity theorists are able to develop a clear specification of this given physical-chemical state. This means that every organism feels pain and is in pain, respectively, if and only if its brain is in exactly that physical-chemical state, which defines pain. In short, this state has to be found in all these organisms when they feel pain. Otherwise, if the mental pain state is realized in different beings through different brain states, the theory fails.
Putnam alleges that such a universal physical-chemical state is very hard to come up with, because in order for them to be in the same physical-chemical state the organisms would have to possess brains of similar physical-chemical structure. Thus, the state in question must for instance not only be a possible state in mammal brains but in reptilian and bird brains, too; and these different brains show actually quite many distinctions.
In addition, this precise physical-chemical state must not be feasible for any organism that cannot have the appropriate mental state. Hence, these creatures with brains unlike ours cannot share our mental states like feelings, regardless of their potentially similar behaviour and similar corporeal qualities. Therefore, organisms who cannot feel pain should not show in any case a brain state that other beings have when they are in pain.
Recapitulating, there is the problem that all creatures that have the same feeling must be in the same physical-chemical state and above all no creature that cannot have this feeling must be in this physical-chemical state at any time.
By considering all these facts, Putnam argues that Identity theory brings up the problem of lacking multiple realization. If mental states are only realized through one brain state, it seems to be more complicated to detect that actually there is for every mental state exactly one single brain state than to find a counter-example. We have millions of nerve cells and therefore indescribable many possibilities for physical-chemical states. To find all of them is apparently a very hard job to do. For the counter-example you only need to take two organisms whose conscious state is equal but the correlated neural state is not and you have refuted Identity theory.
Putnam does not absolutely deny the possibility that sometimes such a species-independent physical-chemical state will be found. Nevertheless, he draws the conclusion for himself that it is much less reasonable to hope for that day, when the required neurophysiological rules will be discovered, than to hope to find psychological rules that explain why different organisms can have equal mental states, though they are perhaps quite different in their physical-chemical structure.
Now I want to present Putnam’s own hypothesis. He points out that mental states are nothing but functional states. Therefore, if you feel pain or are in the state of being in pain you are in some functional state of your organism. Function means that something has a special use. Nature does not create organisms, parts of organisms and functions in them, respectively, without any usefulness. Therefore being in pain is something functional, because if we for instance hurt ourselves this is the simplest way of our body to reveal us that there is some danger, which we have to counteract. Thus, the state of being in pain fulfils a certain function and hence can be called a functional state.
To make the functionality clearer Putnam introduces the example of a Probabilistic Automaton. This is a machine, which is in a certain state, can get sensory input, can go from one state to another, and shows with regard to that state transition a certain motor output. Furthermore, it has a Machine Table for determining every possible state transition and specifying with which probability a state transition occurs. Additionally, Putnam brings in the notion “description”, which is any true representation of a system through any Probabilistic Automaton. Why does he come up with the Probabilistic Automaton? For Putnam it is a good model that can be applied to living beings to explain e.g. mental states. I am now going to talk about this application and the rules Putnam establishes therefore.
Firstly, we can see ourselves as a Probabilistic Automaton. We have sensory experiences and because we value them, we show with certain probabilities some outputs that are reactions. We thereby go from one state into another, for example from a passive pain state into an active reaction state (perhaps we bandage our wounds and then we feel better). To sum up briefly, Putnam thinks all organisms that have the capability of feeling pain (or capability of being in other sorts of mental states) are Probabilistic Automata.
Secondly, all these Probabilistic Automata (organisms) must have a description, which assures functional states. Thirdly, some sort of complex organism such as a swarm of bees does not have the ability to feel pain as an entire organism. Finally, yet importantly, Putnam adds a fourth statement. From the set of all possible sensory inputs, there is for every special state just as pain a subset of input that causes exactly the functional state of being in pain. So if we experience any other subset of sensations, which are not pain-inputs, we will not get into the state of being in pain. Recapitulating, Putnam defines pain as a state of some Probabilistic Automaton that has its rules to detect which inputs are for example „pain-inputs“ and how to go into another state to react with some output. He then applies this process to organisms and recognizes that they have similar probabilities and operate in a same way.
Based on this possible analogy and the functionality that stands behind Putnam considerations he concludes that his hypothesis is much more reasonable even though he does not say that his theory is the one and only. Besides his objections against Identity theory, which I have mentioned already in the first paragraph, he finds functionalism much easier to evaluate by constructing simply an Automaton that is a certain description of an organism and then to describe his properties and research, which inputs cause which state and finally an output, which in the end is transformable to organisms.
In my opinion, Putnam’s approach is a methodological one. I give him credit for his neutral analysis of mental states. It is important what mental states are at all good for, which functions they have. These results into such a hypothesis as that mental states are functional states. I find that very intelligible. Furthermore his theory improves Identity theory in such a way that it allows multiple realization, which was an already spoken to point of criticism. Therefore, it is possible that organisms can be in similar mental states without having exactly the same physical-chemical states. All that is important is the fact that they have some kind of sensory sensors that can cognize the special sensory input and then carry the signal forward through internal rules to get the functional state. As a conclusion, different types of psychical states can realize feelings like pain. You can also imagine this in the sense of a computer program, which can be run on different sorts of computer hardware.
On the other hand, I ask myself, if we were all like machines, it should be also possible for non-psychical beings to have mental states. Because apparently they have all the properties I need to get inputs and convert them and show in the end some outputs. What about the differences between them and me? What lacks here are the real sensations. I am not only in a certain state when I am in pain. I really feel the pain. Are emotions integrated in an Automaton? Due to Putnam, we all are those machines.
To finish, I want to say, that we have a typically philosophical case here: Someone establishes a new theory, which improves failings of older hypotheses, but comes up with many new unanswered questions at the same moment.
