Physicalism
What is it?
There are no immaterial things. All that exists is what is observable in principle.
The physical is often contrasted with the mental.
Beliefs, desires, intentions, feelings, experiences, etc.
Why
physicalism? Two related motivations
The encroachment argument
Man is increasingly understood as a physio-chemical mechanism.
Formerly "mysterious" things have been scientifically explained.
The mental will eventually be explained in this way.
And so, we have no need for immaterial things.
The causal argument (Jaegwon Kim)
- Mental events have physical effects.
- All physical effects have physical causes.
- Effects are not generally or systematically overdetermined.
- Mental events are physical events.
- The problem of the mind
If P is a physical effect, then P has a complete physical causal explanation. If P also has a mental cause, M, then either M is a physical or M is redundant.
A problem for physicalism
The mental is very different from the physical.
Third person vs First person
Public vs Private
Measurable vs Non-measurable
Intentional vs Non-intentional
Divisible vs indivisible
Qualitative vs Non-qualitative
These facts point to the immateriality of the mind.
The mind does not seem to fit within a physicalist framework
Cartesian dualism (Rene Descartes)
Second Meditation: The argument from doubt
I know that I exist and that I am thinking. I do not know that I have a body. If thinking were a property of a body, this would not be possible. Therefore, I am not a body. If it turns out that I have a body, that body is not me but something that I have; I am really distinct from it.
What is the basic intuition here?
The mental is not entailed by the physical. Mental
properties do not appear to be the properties of physical things. They point to
something else altogether.
Sixth Meditation: The argument from indivisibility
… in the first place, that there is a great difference between mind and body, inasmuch as body is by nature always divisible, and the mind is entirely indivisible. For, as a matter of fact, when I consider the mind, that is to say, myself inasmuch as I am only a thinking thing, I cannot distinguish in myself any parts, but apprehend myself to be clearly one and entire; and although the whole mind seems to be united to the whole body, yet if a foot, or an arm, or some other part, is separated from my body, I am aware that nothing has been taken away from my mind. And the faculties of willing, feeling, conceiving, etc. cannot be properly speaking said to be its parts, for it is one and the same mind which employs itself in willing and in feeling and understanding. But it is quite otherwise with corporeal or extended objects, for there is not one of these imaginable by me which my mind cannot easily divide into parts, and which consequently I do not recognize as being divisible; this would be sufficient to teach me that the mind or soul of man is entirely different from the body, if I had not already learned it from other sources.
What is the idea here?
Descartes proves that he has a body: God exists. He would not systematically deceive me.
But there is nothing which this nature teaches me more expressly [nor more sensibly] than that I have a body which is adversely affected when I feel pain, which has need of food or drink when I experience the feelings of hunger and thirst, and so on; nor can I doubt there being some truth in all this. Nature also teaches me by these sensations of pain, hunger, thirst, etc., that I am not only lodged in my body as a pilot in a vessel, but that I am very closely united to it, and so to speak so intermingled with it that I seem to compose with it one whole. For if that were not the case, when my body is hurt, I, who am merely a thinking thing, should not feel pain, for I should perceive this wound by the understanding only, just as the sailor perceives by sight when something is damaged in his vessel; and when my body has need of drink or food, I should clearly understand the fact without being warned of it by confused feelings of hunger and thirst. For all these sensations of hunger, thirst, pain, etc. are in truth none other than certain confused modes of thought which are produced by the union and apparent intermingling of mind and body.
Problems for Dualism
A divided world (an aesthetic problem)
The problem of interaction
The problem of representation
Scientific encroachment
The causation argument
The explanatory gap
There is an "explanatory gap." The mental is not explicable in terms of the physical.
Physicalist theories of the mental
Identity theory
What is identity theory?
The claim that mental events-types are identical to physical event-types.
Problem with the identity theory
Functionalism
What is functionalism?
The claim that mental-event-types are identical to functions of physical things,
e.g., a physical event realizes pain just in case it gains the attention of the organism, causing it to tend to its injuries etc.
Different physical event-types might do this in different species?
Question: Would a physical event that performs the function of pain for an organism be pain if it that event did not hurt, i.e., if the organism did not "feel" pain?
Is there not more to mental events than their functions?
The problem of consciousness
What is the relation between experience and the brain?
Consciousness is qualitative.
The Zombie argument (David Chalmers)
The problem of understanding
Are minds computers?
The Aristotelian argument
The Chinese Room argument (John Searle)
The problem of knowledge
Mary’s room: The Knowledge argument (Frank Jackson)
The problem of mental causation
The mental does not appear to reduce to the physical.
And yet, the mental appears to have efficacy.
How do we explain this?
Is the qualitative character of the mental irrelevant?
Supervenience
theory and Epiphenomenalism
Supervenience is the idea that the mental events are necessitated by physicel events.
Epiphenomenalism is the idea that the mental events do not have efficacy of their own.
Surely the fact that I wanted was vengance (that that is what I wanted, and not something else) had something to do with my striking out at him.
(Fred Dretske) Am opera singer shatters a glass while singing. This was due strictly to the acoustic properties of her singing, not what she was singing about.
Surely the content of our thoughte is not irrelevant to our behaviors in this way.
How might this be accomodated by physicalism?
Eliminativism (Paul and Patricia Churchland)
There are no mental events. The idea that there are is just "folk psychology."
Pan-psychism (David Chalmers)
The physical is not what we suppose. The mental is a basic feature of the universe.
Thomism (Thomas Aquinas)
The soul is the form and living principle of the body. The human person is not two substances, as on Descartes's view but one substance having two principles.
