Here's what I just posted to the other person. Perhaps you can tell me where I'm going wrong, because it seems to me that physicalism is impossible.

The UMD paper you link to elsewhere describes the central proposition of mind-brain identity physicalism as follows:

> a pain or a thought is (is identical with) some state of the brain or central nervous system

> ‘pain’ doesn’t mean ‘such-and-such a stimulation of the neural fibers’... yet, for all that, the two terms in fact refer to the very same thing." [emphasis in original]

(If you search for this second sentence and see it in context, you will see that substituting 'thought' for 'pain' is a fair reflection of the document's position.)

But this is problematic. Consider the following:

1. Thoughts are, at least sometimes, about reality.

2. My thought in some way refers to the object of that thought. Otherwise, I am not thinking about the thing I purport to be thinking about, and (1) is false.

3. That reference is not limited to my subjective, conscious experience of that thought, but is an inherent property of the thought itself. Otherwise, again, (1) is false.

4. Physicalism says the word "thought" and the phrase "a particular stimulation of neural fibers" refer to the same thing (from document above).

5. "A particular stimulation of neural fibers" does not refer to any object outside itself. Suppose I'm thinking about a tiger. You cannot analyze a neural state with a brain scan and find a reference to a tiger. You will see a bunch of chemical and electrical states, nothing more. You will not see the object of the thought.

6. But a thought must refer to its object, given 2 and 3. So "thought" and "particular stimulation of neural fibers" cannot refer to the same thing. (I will grant, and it is my position, that the latter is part of the former, but physicalism identifies the two.)

This seems to imply physicalism is false.

What step am I going wrong on?

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GoblinSlayer 5 days ago | parent [-]

5. If the reference exists, it doesn't disappear if you don't see it. You should see better. Reference has a corresponding material fact too.

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geye1234 4 days ago | parent [-]

Point 5 is sound, and it's actually impossible for a configuration of neural fibers to refer to something outside itself (and therefore, if physicalism is true and thought = neural fibers, it's impossible for a thought to refer to something outside itself, which would falsify point 2). Here's why:

The reference can't exist in the thought if "thought" and "a particular stimulation of neural fibers" refer to the same thing. There is no reference in the fibers. You can't "encode" a reference to something else in the physical brain (or any part of the body).

This is because a reference must in some way refer to its object (obviously). But a reference can only be referred to its object by something else. The word "tiger", or a picture of a tiger, refer to an actual tiger only when there is a mind to give them that meaning. But "a particular stimulation of neural fibers" cannot refer to any object, because there is nothing that can give it that meaning. A word or a picture or anything extra-mental can be given meaning by a mind, but when we are talking about the mind itself, this is impossible.

	▲	GoblinSlayer 3 days ago \| parent [-]
		If meaning is given, it's a structural property of mind and is encoded in brain like any other structural property.