by jimwalton » Sun Mar 11, 2018 4:53 pm
> Physical damage to the brain can lead one into (possibly permanent) unconsciousness or a coma as well as drastic personality changes. You would propose there's other elements at work for consciousness and the self so why do we see such dramatic changes from physical means alone?
My response to this is that we also see damage to consciousness that comes from causes other than physical damage. Sometimes people are damaged through emotional trauma or psychological factors that have nothing to do with physical trauma to the brain. There are many elements at work for consciousness and the self besides physical ones. So I don't see "such dramatic changes from physical means alone."
> I don't see why they don't question why the mentally impaired or brain damaged couldn't use whatever other processes that go on within a person's thinking to compensate for their physical problems.
I know they're always working on things, and technology will help in the quest. The brain, as deeply as it is understood, is still not understood all that well. It is capable of amazing things, both positive and negative (psycho-somatic symptoms, illnesses, and even healings).
> But yet we never see this occur.
I wouldn't be so sure about this one just yet.
> Why should we trust a reasoning that we arrive at through mysterious processes that we can't explain (if I'm understanding you right and you do believe reasoning is possible)?
Oh, I didn't say just through processes we can't fully explain. What I said was that if the evolutionary process is genetic mutations + the blind processes of natural selection, and since "truth" is not a quest of the biological survival focus, we cannot be certain that any emerging thoughts are anything but a combination of these processes, and therefore nothing to do with truth and reason. As Alvin Plantinga says, "First, the probability of our cognitive faculties being reliable, given naturalism and evolution, is low. (To put it a bit inaccurately but suggestively, if naturalism and evolution were both true, our cognitive faculties would very likely not be reliable.) But if I believe in both naturalism and evolution, I have a defeater for my intuitive assumption that my cognitive faculties are reliable. And if I have a defeater for that belief, then I have a defeater for any belief I take to be produced by my cognitive faculties. That means I have a defeater for my belief that naturalism and evolution are true. I cannot rationally accept them. Therefore, if I can't accept them—the pillars of contemporary science—then there is serious conflict between naturalism and science.
Atheists and scientific naturalists concur.
Darwin: "With me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind?"
Thomas Nagel: "If we came to believe that our capacity for objective theory (e.g., true beliefs) were the product of natural selection, that would warrant serious skepticism about its results."
Barry Stroud: "There is an embarrassing absurdity in [naturalism] that is revealed as soon as the naturalist reflects and acknowledges that he believes his naturalistic theory of the world. … I mean he cannot it and consistently regard it as true."
Patricia Churchland: "Boiled down to essentials, a nervous system enables the organism to succeed in the four Fs: feeding, fleeing, fighting, and reproducing. The principle chore of nervous systems it to get the body parts where they should be in order that the organism may survive. … Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival. Truth, whatever that is, definitely takes the hindmost."
The principle funfunction or purpose, then, of our cognitive faculties is not that of producing true or near true beliefs, but instead that of contributing to survival by getting the body parts in the right place. What evolution underwrites is only (at most) that our behavior is reasonably adaptive to the circumstances in which our ancestors found themselves; it doesn't guarantee true or mostly true beliefs. Our beliefs might be mostly true, but there is no particular reason to think they would be: natural selection is not interested in truth, but in appropriate behavior. What Churchland is suggesting is that naturalistic evolution—that is, the conjunction of metaphysical naturalism with the view that we and our cognitive faculties have arisen by way of the mechanisms and processes proposed by contemporary evolutionary theory—gives us reason to doubt two things: (a) that a purpose of our cognitive systems is that of serving us with true beliefs, and (b) that they do, in fact, furnish us with mostly true beliefs.
> Physical damage to the brain can lead one into (possibly permanent) unconsciousness or a coma as well as drastic personality changes. You would propose there's other elements at work for consciousness and the self so why do we see such dramatic changes from physical means alone?
My response to this is that we also see damage to consciousness that comes from causes other than physical damage. Sometimes people are damaged through emotional trauma or psychological factors that have nothing to do with physical trauma to the brain. There are many elements at work for consciousness and the self besides physical ones. So I don't see "such dramatic changes from physical means alone."
> I don't see why they don't question why the mentally impaired or brain damaged couldn't use whatever other processes that go on within a person's thinking to compensate for their physical problems.
I know they're always working on things, and technology will help in the quest. The brain, as deeply as it is understood, is still not understood all that well. It is capable of amazing things, both positive and negative (psycho-somatic symptoms, illnesses, and even healings).
> But yet we never see this occur.
I wouldn't be so sure about this one just yet.
> Why should we trust a reasoning that we arrive at through mysterious processes that we can't explain (if I'm understanding you right and you do believe reasoning is possible)?
Oh, I didn't say just through processes we can't fully explain. What I said was that if the evolutionary process is genetic mutations + the blind processes of natural selection, and since "truth" is not a quest of the biological survival focus, we cannot be certain that any emerging thoughts are anything but a combination of these processes, and therefore nothing to do with truth and reason. As Alvin Plantinga says, "First, the probability of our cognitive faculties being reliable, given naturalism and evolution, is low. (To put it a bit inaccurately but suggestively, if naturalism and evolution were both true, our cognitive faculties would very likely not be reliable.) But if I believe in both naturalism and evolution, I have a defeater for my intuitive assumption that my cognitive faculties are reliable. And if I have a defeater for that belief, then I have a defeater for any belief I take to be produced by my cognitive faculties. That means I have a defeater for my belief that naturalism and evolution are true. I cannot rationally accept them. Therefore, if I can't accept them—the pillars of contemporary science—then there is serious conflict between naturalism and science.
Atheists and scientific naturalists concur.
Darwin: "With me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind?"
Thomas Nagel: "If we came to believe that our capacity for objective theory (e.g., true beliefs) were the product of natural selection, that would warrant serious skepticism about its results."
Barry Stroud: "There is an embarrassing absurdity in [naturalism] that is revealed as soon as the naturalist reflects and acknowledges that he believes his naturalistic theory of the world. … I mean he cannot it and consistently regard it as true."
Patricia Churchland: "Boiled down to essentials, a nervous system enables the organism to succeed in the four Fs: feeding, fleeing, fighting, and reproducing. The principle chore of nervous systems it to get the body parts where they should be in order that the organism may survive. … Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival. Truth, whatever that is, definitely takes the hindmost."
The principle funfunction or purpose, then, of our cognitive faculties is not that of producing true or near true beliefs, but instead that of contributing to survival by getting the body parts in the right place. What evolution underwrites is only (at most) that our behavior is reasonably adaptive to the circumstances in which our ancestors found themselves; it doesn't guarantee true or mostly true beliefs. Our beliefs might be mostly true, but there is no particular reason to think they would be: natural selection is not interested in truth, but in appropriate behavior. What Churchland is suggesting is that naturalistic evolution—that is, the conjunction of metaphysical naturalism with the view that we and our cognitive faculties have arisen by way of the mechanisms and processes proposed by contemporary evolutionary theory—gives us reason to doubt two things: (a) that a purpose of our cognitive systems is that of serving us with true beliefs, and (b) that they do, in fact, furnish us with mostly true beliefs.