Daniel Morgan said:
Certainly, the brain and mind are one and the same in my worldview. One does not exist without the other. However, supervenience and epiphenomena and many other ideas do not make my stance necessarily reductionist (to show thought A = molecule B doing C). Think of fire for a moment. Knowing all that there is to know about hydrocarbons, and knowing all that there is to know about oxygen, we still cannot experience combustion except through the perception of fire as a visual and thermal phenomenon. Experiencing the heat on your face is quite different than calculating the energy of C=O and O-H bond formation against the energy of C-H and O=O bond formation. Being inside our own minds, we are experiencing, I am sure, nothing but biochemical interactions, not qualitatively different than combustion. However, we perceive these biochemical phenoemna first-hand, since they constitute our brains, and we're not viewing them objectively (as with fMRI or CT scans) -- we're feeling the heat and seeing the light of these phenomena.
I'm just trying to point out here that I don't necessarily disagree with the comment on watching neurons fire and correlating it to mental activity.
Doing that (observation) is like doing the calculation for the enthalpy of combustion (the heat that will be given off). The reality of fire, however, can include a completely different perception, to which you would be completely ignorant of, and without the ability to describe, unless you are close enough to the phenomenon to experience it firsthand -- heat and light.
Weasel words like supervenience and epiphenomena bake no bread.
You can say that a set of properties at a higher plane of organization are not equipollent with a set of properties at a lower level of organization. There is more to a Bach fugue than the diatonic scale.
But if you’re a physicalist, then you still have to treat thought, consciousness, qualia, and the like as something physical in itself, and not merely the byproduct of a physical process.
Thus, the effect, and not merely the underlying cause, needs to be detectable by physical means and subject to physical analysis, viz. what is the chemical position of thought?
I don't think that, because of the fundamental disconnect between experience/perception and objective observation, we can ever run wires to your brain and put up on a screen what you're seeing, or "feel what you're feeling". Possibly we never will be able to. Part of mental processes, I agree, is in the subjective experience/perception and cannot be observed. But, does this cause me to invoke some unknown, immaterial substance? Why would it?
i) Scientifically speaking, you don’t know what you can’t show. Even if physicalism were true, if it cannot be known to be true because it cannot be shown to be true, then it’s just an unverifiable hypothesis. The fundamental disconnect renders physicalism unprovable.
ii) The aim of science is to explain every phenomenon according to a public, third-person description.
Due to the privacy of mental events, this cannot be done—which is why some physicalists deny mental states altogether.
iii) There is also the fundamental issue of our starting-point. Mine is Cartesian, yours is not.
You operate with a presumptive materialism. I regard this as a flawed methodology.
From an epistemic standpoint, the external world is a secondary phenomenon, for we experience the external world via the mind. Therefore, the mind enjoys epistemic primacy.
We enjoy an immediate experience of our own mental states, and only a mediated experience of material states.
No physical experiment can overturn the primacy of the mind because any physical experiment will, itself, be a mediate object of knowledge, filtered through the mind.
iv) In our experience, mental properties differ from material properties. A thought of blue is not a blue thought.
Thoughts lack primary qualities, viz. size, shape, solidity.
This is a direct deliverance of consciousness. A primitive datum.
And since this is an immediate, self-presenting state, there can be no hiatus between appearance and reality. We don’t appear to feel pain. We either feel pain or we don’t.
v) Now, a physicalist will say that this subjective impression is illusory. That, in fact, this impression is explainable by a physical process.
He can say that, but he can never show that. There is no presumption in favor of physicalism. To the contrary, the presumption is always in favor of mind over matter.
And this is more than a prima facie presumption. We begin with the mind because that’s the only place we can ever begin. And the incorporeal character of the mind is given in the very act of consciousness.
vi) We are not invoking an unknown substance. To the contrary, we are invoking something we know much better than any material substance.
The ability to describe experience and perception using Na/K potentials across your neurons in terms of intensity and frequency is real. In other words, intense pain correlates to higher frequency neural processes as well as a greater concentration of ions released at synapses. I can thus "see" your pain, but seeing it and feeling it are two completely different things. I can make a graph of the flux of ions across your neurons and show the valleys and troughs correlating to your experience of pain. I cannot show your pain itself on a screen for others to view. Your pain is indeed "reducible" to Na/K potentials, but can I say that I can "describe" the experience/perception of pain unless I have felt it? No.
A dualist isn’t going to deny that pain has a physical aspect. If I stick a needle in your arm, the pain will travel to the brain via a nerve impulse.
Obviously the pain has a physical source of origin (the pin prick) and well as physical mode of transmission. So the fact that to some extent we can map that process is hardly at odds with dualism.
How can creatures who experience mental processes first hand, and are even using them in trying to observe others', ever hope to have some sort of understanding of their own experience from an objective standpoint? They can't. So?
Except that science is all about achieving an objective (public, third-person) description of reality. And a materialist will generally regard the scientific method as the royal road to knowledge. Empirical science is the source and standard of knowledge.
How is skeptically and tentatively accepting the rationality of any particular conclusion undercut by the origin of the brain? This is what we've yet to clarify. I pointed out in the beginning that I was willing to lay aside the question of soul/spirit and consider only whether or not human brains are the product of evolution (with or without divine guidance) or a special act of creation, which I dubbed "poof", but you cannot dispute the accuracy of the description. Something which doesn't exist, suddenly does = poof.
It’s precisely the accuracy of the description that I can dispute. For one thing, it leaves the agent out of view (God). It also confuses the origin of the world (creation ex nihilo) with the origin of the soul (creationism or traducianism).
You have a bad habit of repeating the same mistakes after the error has been called to your attention. I’ve corrected you on this, but you respond like a continuous loop-tape.
What evolution depends upon is, by the naturalistic framework, the laws of physics. Even the most "chance" of processes are not what we would call "unbounded". That is, the energy distribution of a bunch of particles at a given temperature (ie with a particular average kinetic energy) can be represented with a Gaussian distribution. Why do I mention this? Well, even the most indeterminable outcomes of physical states still obey the laws of physics (in the naturalistic worldview). Therefore, when we speak of a brain being created by naturalistic processes, and humans inheriting a "monkey mind", I still have yet to see why this necessarily entails irrationality. The "monkey mind" itself must obey the laws of physics, in a naturalist's worldview, and no known natural processes can be considered completely beyond understanding or description (even if the states fall under a distribution of probabilistic outcomes, as with quantum mechanics).
The laws of physics themselves are hardly "irrational", even if indeterminable due to the number of variables involved. When considering all natural processes, chance/random or no, "any" outcome is not possible, just "many". This provides us with a sort of foundation to counter some sort of presumed connection between irrationality and natural processes.
You’re committing several category mistakes:
i) While the laws of nature are not irrational, they are irrationable. They may not be unreasonable, but they are unreasoning.
ii) There is, in addition, a big difference between the significance of natural law in a Christian worldview and a secular worldview.
In a Christian worldview, there is a mind behind the mindless laws of nature; but in a secular worldview, there is no mind behind the mindless laws of nature.
So secularism upholds the primacy of matter over mind. Matter is primary, mind is secondary.
iii) Moreover, determinism and rationality are two different things. For example, you can have a deterministic randomizing program, such as a computerized slot machine.
So even if we were to subscribe to a hidden variables version of quantum mechanics, which left the laws of nature deterministic from top to bottom, that would not underwrite the rationality of our cognitive faculties.
iv) Furthermore, natural laws are not truth-conducive. Natural laws are impersonal. They do not select for true beliefs.