Show me!

Daniel Morgan said:

“That isn't what I said -- I pointed out that our very existence demands at least one substance, and from there, additional substances ought to be substantiated, which you disagree with--you think I'm being a "card sharp" again, it appears.”

This would be okay unless you tacitly identify the primary substance as matter, and then demand a special burden of proof for “additional” substances.

“Second, if I can't show your perception on a screen, it doesn't mean physicalism is unfalsifiable, simply that I don't know if that particular aspect of the mind can be rendered into an observable phenomenon. Feeling the heat on your face, and somehow conveying that as an observation to others, requires transferring it to another medium (telling them in words, or replicating the experience for them by forcing them to experience it). Experiencing our own mind (feeling the heat from it) may not be reducible to some simple physical description, but that doesn't mean it isn't correlated by these ‘potential graphs’ I was describing which monitor brain activity.”

The disconnect isn’t limited to perception generated by an external stimulus. It’s limited to mental states generally, whether it’s a percept or dream or memory or interior monologue or unadorned idea. None of our thought-content is accessible to scanning technology.

“Third, as I just explained, you can indeed make a graph of the electrochemical potentials and correlate them to what you report that you feel. In that sense, we can ‘show’ the physical mechanism causing you to ‘feel’. Your feeling is itself a physical mechanism, just another step in the causal chain of biochemistry.”

What you’ve done is to graph the effect of cognition, not the underlying cause.

“Why should we assume, if the physical mechanism of pain is granted, that there is no physical mechanism of perception?”

A dualist doesn’t deny that perception in general or pain in particular may often have a physical component. The problem lies in reducing pain or perception to a physical mechanism.

I can dream of being in pain in the absence of any external, pain-inducing stimulus.

“You are not explaining what properties of the immaterial confer perception, any more than you claim that a physicalist explains the properties of matter that give rise to consciousness. It's an argument from ignorance for both of us -- if neither can give a satisfactory explanation, do we each claim victory?”

Several problems with this reply:

i) I can know what mental properties are irrespective of what role they play in relation to sensory perception. I can identify their existence apart from my identification of their function.

ii) I’m less concerned with their relation to perception than I am with their relation to conception.

iii) Likewise, one could be ignorant of the relation between mind and matter without being ignorant of mind and matter, irrespective of their interrelation.

“If you know much about these algorithms, you know that they aren't perfectly random, by dint of the limitations of machine language.”

That misses the point of the illustration. You could have a randomized result which is the product of a deterministic process. There’s no logical relation between determinism and rationality.

Even if the laws of nature were deterministic from top to bottom, that doesn’t select for true beliefs.

“So you're saying that rationality isn't itself a function of physical laws?”

That’s right. Physical laws are impersonal and unreasoning. How could rationality be a function of a mindless process?

At best that could only occur if there were a mind behind the mindless laws of nature.

“Show me rationality without them. You can't. Show me a mind which isn't underwritten by the very much deterministic laws of nature.”

There are different ways of answering this question. But, to take one example, in order for mental states to be underwritten by the laws of physics, mental states would have to have physical properties. Otherwise they would not be subject to the laws of physics.

Now, a thought of blue is not a blue thought. A thought of chocolate is not a chocolate thought. A thought of noise is not a noisy thought. A thought of perfume is not a fragrant thought. A thought of velvet is not a velvety thought.

Moreover, one can only think of a physical state if one’s reasoning process is not, itself, a physical state.

A physical state is non-referential. A rock has no truth-value.

A petroglyph can have truth-value because a rational agent used the rock as a medium of communication between one mind and another.