Philosophy of Mind

Philosophy of mind is the philosophical study of the nature of the mind, 
mental events, mental functions, mental properties, and consciousness. 
These areas give rise to some very difficult problems and questions, and 
there are many opinions as to their solutions and answers. This article 
attempts to suggest the scope of the philosophy of mind and indicate some 
of the important questions, but does not provide answers.

What is the mind?

Does the word mind refer simply to a collection of particular thoughts, feelings, 
and so forth, or does it refer to some entity over and above those particular 
thoughts, feelings, and so forth? If mind refers to an entity, is it composed of 
the same kind of substance as physical objects, or of some other substance? This 
article does not propose to answer these questions, but to outline what other 
questions any answer might involve.

Other questions could be asked regarding the mind; we might raise the mind-body 
problem. If we suppose that the mind is some sort of mental substance, we might 
ask: Is there some way to explain mental substance in terms of physical 
substance, or not?

Mental events

Suppose instead that we deny that the mind is some mysterious substance, and we 
hold instead that there are only mental events and that "the mind" designates no 
more than a series of mental events? We can still inquire about the relation 
between mind and body a different way, in terms of the relation between mental 
events and physical events. We can ask: Are mental events totally different from 
physical events, so that you can't explain what mental events are in terms of 
physical events; or are mental events somehow explainable as being the same as 
physical events - a view known as token-physicalism? For example, when John 
feels a particular pain P (at a particular time T), a particular mental event 
M is occurring (at a particular time T); now is that pain, P, even possibly the 
same as something that occurs in John's brain, such as the firing of some 
special group of neurons, M?

Mental properties

Another question commonly asked is whether mental properties (or states, or 
kinds, or [equivalently general term]) just are physical properties. Is the 
mental phenomenon we call 'pain' really just, say, firing C-fibers in the 
brain? This view is known as type-physicalism (or type-identity theory). A 
common argument against this view is known as the argument from multiple 
realizability: since animals we commonly attribute as being in pain have 
completely different neurophysiological systems, and thus completely different 
physical properties, it follows that pain cannot be one particular physical 
property, i.e., firing C-fibers found in humans. After all, surely dogs, 
other animals, and even reptiles are capable of feeling pain. (We could go as 
far as saying that aliens with utterly disparate physical systems are also, at 
least possibly, capable of feeling pain.) This type of argument is generally 
taken to be an argument against another related view known as scientific 
reductionism.

Reductionism

Identifying the mind with physical substances or properties is one direct 
form of materialism, and claiming that psychological theory (whichever flavor 
you wish) is reducible to scientific theory is another, albeit indirect, 
form of materialism. If we can show that all of psychology is reducible to 
neurophysiology, and in turn, neurophysiology is reducible all the way 
(perhaps via other special higher-order sciences, like chemistry) down 
to physics, then what we've shown is that mind is nothing above and beyond 
the physical. In effect, it is a two step process: i) reducing languages 
to each other, and ii) then claiming that the ontology (or objects) of the 
reduced science (psychology) is identical to the ontology of the reducing 
science (neurophysiology).

Functionalism

As alluded to above, many philosophers accept the thrust of the multiple 
realizability argument and thus reject both type-physicalism and 
redunctionalism wholesale. The argument has motivated another view known 
as functionalism which holds that mental states aren't physical, rather, 
they're functional. A functional state describes a relationship between 
certain inputs (sensory stimuli), outputs (behavior), and other mental 
states. A pain is functional in virtue of having a certain causal role. 
That causal role is determined by certain input stimuli and mental states, 
and determines future behavior and mental states. So although pain may not 
be identical to some one (first-order physical property like) firing 
C-fibers, it's at least identical to some (higher-order) functional state 
F. Generally, functional states are specified in terms of Turing machines 
states, which are completely describable by Turing machine tables. And so, 
one version of functionalism, machine-functionalism, identifies mental 
states with Turing machine states. Arguments such as Putnam's Twin Earth 
thought experiment, and Lucas' Godelian argument have been the forerunners 
against functionalism.

So far we've presented several different questions that the philosophy of 
mind asks: What is the mind, a substance or just a series of mental 
events? Is the mind somehow reducible to, or explainable in terms of, the 
body? Are mental events somehow reducible to, or explainable in terms of, 
physical events? Each of these questions are ways of interpreting the 
more ambiguous questions we started with, such as, "What is the mind?" 
and "What are mental events?"

What is involved in each type of cognitive process?

We can also ask questions about the different specific cognitive processes, 
and of course we might ask what cognitive processes in general are supposed 
to be. In that case, we'd be asking what distinguishes a cognitive process 
from any other kind of process. That is another way of putting the 
mind-body problem. We can also ask a series of more specialized questions, 
about each individual cognitive process. We can get the answers through 
cognitive science.

Take perception as an example. Philosophers ask what is going on when we 
perceive something -- when we see, hear, taste, touch, and so on. But 
philosophers are not interested in the particular mechanisms that allow 
us to see -- for example, they do not study the shape of the eye or how 
the optical nerve carries information to the brain. They are interested 
in even more basic questions. They ask: Do we perceive physical objects 
directly with our senses, or do we form mental images of some sort, which 
we use to represent physical objects and their properties? These are 
questions raised by the philosophy of perception. The philosophy of 
perception is all about how our minds come in contact with the world 
outside our minds.

Another example is the will, or volition. When we choose to do something 
we are using our wills, or engaging in volition. There is, of course, one 
special and very difficult question that philosophers ask about this 
process, namely, is the will free? If Mary decides to walk across the 
room, that seems to be entirely up to her; she could have chosen otherwise. 
But if the universe is determined, and especially if our will really is 
after all just a physical process, then it certainly does seem as though 
Mary didn't have control over everything that led up to her deciding to 
walk across the room. So was she free or wasn't she?

What is consciousness?

Consciousness is one of the most problematic areas of modern philosophy 
and neuroscience. From the perspective of the naīve or direct realist it 
is simply the processes that occur in the brain between stimulus and 
response. The issue is, however, far more complex than this, for instance 
in imagining, lucid dreaming and dreaming the subject seems to be 
perceiving brain activity and modern fMRI studies show that similar areas 
of brain are used for perception, imagination and dreaming. How does the 
brain see its own activity? Would this require an absurd little man or 
homunculus in our heads? Or is there some fascinating phenomenon or process 
at work? This is just one of many problems associated with the study of 
consciousness. See the link to consciousness for more information.


Frame issues

A final class of questions emerging from this aspect of philosophy concern 
the validity of the commonsense categories employed. Must it be the case 
that determinism rules out free will, or is it that one or both of these 
categories has been poorly defined? Does the rule against multiplication 
of entities force materialists to exclude higher-order entities such as 
semantic systems, or have we endowed 'material' with unwarranted properties? 
Is the term 'natural' meaningful if we deny that it has an opposite? What 
precisely is an event?