Posted: April 2nd, 2015
Introduction to Philosophy
Lecture 15
Introductory Remarks: Carruthers makes some interesting moves in this article. The most interesting is when he takes some premises of a criticism of the identity thesis and turns them into an argument for the identity thesis.
Strong materialism – all mental states and events are in fact physical states and events.
This is strong materialism since it leaves no room for some mental states not being physical states. The identity thesis is strong materialism, but it is not a theory of meaning. It doesn’t say that “pain” means c-fibers firing. The identity thesis is not committed to saying that pain may be analyzed or defined in terms of descriptions of brain processes, cause that would be absurd (crazy even!) What isn’t crazy is thinking that “Pain=c-fibers firing” is a contingent, non-necessary thesis about our words and what they refer to in the world. Our words for states of mind refer to the same thing as our words for the physical brain states. Another example may help. Morning Star and Evening Star refer to the same celestial body, Venus, but the two words have different meaning. Thus Pain and C-fiber stimulation both refer to the same physical event, but they don’t mean the same thing.
Carruthers give a counter-argument that is quite elegant. He agrees that we very firmly believe that some mental states and events are causally necessary for the physical events, at least what we commonly call mental states. But then he turns that claim to the advantage of the physicalist by giving a physicalist explanation of the event of experiencing pain:
This argument turns a criticism of mind/body dualism into an argument for the identity theory. We have noted that dualism has a hard time explaining how a so-called “mental state”, such as a decision to move my body, could cause a physical event, such as the movement of my body. But, obviously, these so-called “mental states” do cause physical events. So, Carruthers concludes, these so-called “mental states” must just be (i.e., be identical to) states of the brain and/or central nervous systems…because only physical brain states could cause physical behavior. In other words, the physicalist could just bite half the bullet and agree that mental states cause physical events, but that a physical description can be given for the mental event and thus still save causality and the identity thesis. This is easier to see if we remember that physical events don’t mean the same thing as mental events, though they may refer to the same thing.
The arguments as stated conclude only that some mental events (those that cause physical events) are identical with brain states. But, we can ask how many…most, some? It does seems like mental events can at least sometimes cause physical events. And, it seems unlikely that some mental states are brain events, but others are not. So, it seems reasonable to conclude, that if the argument succeeds, that all mental states identical to brain states.
So, does the Argument Succeed? Well it is valid, that is, if the premises 1 and 2 are both true, then the conclusion 3 is also true. And it certainly seems like both 1 and 2 are true. That is, 1 is a deeply rooted common sense belief, and 2 is a deeply rooted scientific belief.
The only reasons for doubting that the argument succeeds are the various arguments against the identity theory, which Carruthers considers next.
Leibniz’s Law – Identical things share identical properties.
This law points to a general strategy in attacking the identity thesis. If A and B are identical, then whatever properties A has, B has also, and vice versa. That is, if A and B are the very same thing, then “they” must have exactly the same properties. On the other hand, if A and B have different properties, then they cannot be identical. So, if mental states and physical states have different properties, they cannot be identical. This strategy is applied in the following:
The dualists often claim that the physicalist analysis is in violation of this principle with regard to the following:
1) Certainty – i) We can be certain the existence of our mental experiences.
iii) So (by Leibniz’s law), conscious experience (mental states) are not identical with brain-states.
Carruthers’s Reply – The premises may be true, but the conclusion still fails since Leibniz’s Law doesn’t apply to things to contexts or situations in which intentions are involved, as in, intended reference. That is, Leibniz’ Law does not apply in contexts involving mental states such as desire and belief. For example, suppose I have a belief that my neighbor likes gardening, and so she has the “property” of being believed by me to like gardening. I simply do not know that this is what she does for a living. So I also don’t believe that the President of the First National Bank (which is my neighbor’s job, though I don’t know that) likes gardening (and so does not have this “property”), it does not follow that my neighbor is not in fact the bank president. She’s still the president, she is still identical with the person who holds that title, even though I don’t intend to refer to her in my beliefs. Thus, intensions put a monkey wrench in the certainty based criticism of the identity thesis. Another example; one might know that Mr. Hyde is a murderer, and not know that Dr. Jekyll is a murderer, since you are unaware of Dr. Jeckyll. If we were to apply Leibniz’ law, it would follow that Dr. Jekyll and Mr. Hyde are not the same person, which of course they are(?).
2) Privacy – i) Conscious states are private, they are only accessible to the person who has them. Brain-states are not private.
iii) So (by Leibniz’s law), conscious states are not identical with brain states.
Carruthers’s Reply – Privacy is ambiguous, that is, it can have at least two senses. In the first sense, privacy could mean exclusive knowledge. That seems like another intention based approach addressed by the above. In the second sense, privacy can be taken to mean ownership. If that is what is meant – owned, then Carruthers says that it is simply false that anybody else can own your brain states as they own a car. If you have brain state of having a sneeze, that is your sneeze, which is why we say “bless you” to the owner of the sneeze, that is, the one who sneezed! Thus brain states are private and identical with mind states.
3) Value – i) A thought can be wicked and a desire can be admirable.
iii) So (by Leibniz’s law), conscious states are not identical to brain states.
Carruthers’s Reply: We might be tempted to say that ii must be false since it seems quite right to that a stabbing, a physical event, is subject to moral evalution or norms. That reply may well be true, but if it is true, then value is defeated in the same way as certainty since the quality of wickedness is an intentional property as well.
4) Colors (and Feelings) aka Jackson’s Qualia argument –
iii) So (by Leibniz’s law) conscious states are not identical to brain states.
Carruther’s Reply: After images aren’t literally green in the way that grass is green. When we say that a sensation (such as an after-image) is green, what we mean is that it is the kind of experience we typically have when looking at something that (literally) is green. What we mean is only that the sensation is “of” something green—that is, it is caused by something that (literally) is green. But in this sense, brain states can be “green,” that is, they can be of something green—they can be caused by something that (literally) is green.
5) Complete Knowledge –
iii) So mental experiences are not physical states.
Carruthers’s Reply: both i and ii can be true, but the argument is invalid and fails because “knowledge” is not used the same way in both i and ii. The first is propositional knowledge (knowledge about facts) and the second is about practical knowledge (recognitional knowledge). Carruthers argues that this argument is problematic because “knowledge” means different things in premises (1) and (2). Knowing that something is red is different from recognizing the red things. A blind person can know you drive a red car, but a blind person wouldn’t be able to recognize or have a practical experience of your car as a red car. So ii is probably not true, and the criticism is therefore invalid.
iii) So (by Leibniz’s Las) conscious states are not identical with brain-states.
Carruthers says that i is obviously true, so all of the action is on ii. Can merely physical states be intentional. That is, can a body alone have an intention? We talked in class about the possibility of a thermostat having beliefs, it’s too cold in here!, but what about intentions? Notice his cruise missile example and all the scare quotes! Is it plausible to say that machines can have intentions, beliefs, and desires? More on this later.
Functionalism – anything that plays a certain causal or functional role is mental state.
Eliminative Materialism – a neuroscience account of mental life that may not mesh well with the concepts we use to describe our mental life in other contexts. The material of the body/brain is sufficient to describe the mind, thus we can eliminate the minds in the simplest explanation. The mind is a complicated delusion, or simply false consciousness!
1) Inverted spectrum. To illustrate, consider the possibility of one person seeing an inverted color spectrum. Call this person Tony. Tony’s vision is very different from yours. When you see red, he sees violet. When you see indigo, Tony sees orange. Now, functionally, Tony’s mental state picks out the right item when you say “hand me that red apple” even though Tony has the experience of seeing a violet apple. He has always had an inverted spectrum, so he virtually always identifies the proper items, but he doesn’t see the right colors. His odd color defect is still performing the right functions.
2) Absent Qualia. We can imagine fancy machines or complicated human systems, p329, that perform the functions of mental states very well, even functioning as pain, pleasure or whatever really would perform. The complaint of this scenario is that such systems would not be feeling pain, pleasure, or probably anything else.
To illustrate this point Churchland discusses a number of historical examples of concepts that were eliminated by advancing science. For example, people used to think that there existed a substance called “phlogiston” in woods and metals; they believed that wood burning or metal rusting was just phlogiston being released into the air. However, better science revealed that burning and rusting were the result of wood and metal gaining oxygen, not losing phlogiston. Thinking that phlogiston existed and could be explained was a mistake; it was therefore eliminated from our ontology. Eliminative materialists think that the same is true of concepts like belief, pain, sadness, and so forth. As we better understand neuroscience, we can eliminate those concepts in favor of concepts that map physiology directly. In other words, as neuroscience progresses, we can do away with pesky notions and ideas about the mind, that is, eliminate it via a scientific explanation of the brain. The following are arguments why folk psychology is primitive and confused, and thus is better eliminated and rejected in favor of neuroscience.
1) Theoretical Impotence. Folks psychology has a poor track record explaining, predicting and manipulating it’s subject matter. For goodness sake, we can’t even define sleep! We don’t understand how learning is performed. We don’t understand how some differences in intelligence are grounded. We have no idea how memory works. Folk psychology can’t explain much of anything, not even mental illness. As such, stick the mental and the psychological in the trash bin of history and defer to neuroscience and psychiatry to do the trick. And when we are talking about damaged brains, folk psychology and the mental states crowd are really outdoors and don’t even know where to begin in identifying, classifying, and treating.
2) An Heirloom or Antique Theory. Any theory started in a ridiculous place, especially the folk theories. The early folk theory of astronomy was geo-centric, the early folk theory of chemistry had only 4 elements. All the other theories have been refined by progress, but the folk psychology survives pretty much intact, until recent pressure to reform coming from neuroscience. It seems more likely that our views are stubborn and resistant to arguments and change rather than we got it so right so early…2000 years.
1) Introspection shows direct evidence of the mental. EM is false because we introspection reveals the direct existence of pains, beliefs, desires and all sorts of mental events and entities. How can it be that the mind doesn’t exist? The existence of the mental states is obvious.
Churchland’s Reply. The medieval citizens were sure, through introspection, of the geo-centric solar system, the existence of witches, and the familiar mental states. To assert that any introspected concept is real is simply to beg the question under scrutiny.
2) EM is self-effacing. The statement “familiar mental states do not exist” is meaningful only if we have beliefs, intentions, and knowledge. But those all seem like mental states as well. Thus EM is hoisted on its petard.
Churchland’s Reply. This begs the question as well, but on the meaning of certain epistemic terms. What counts as a belief and knowledge should change if we change the nature of the mental stage for belief. To insist on the old conceptions of justification et al is to beg the question again.
3) The Alarmist Cry. EM is making mountains out of molehills, or better put, throwing the baby out with the bathwater before checking the baby! Maybe a matured neuroscience will be selective about what folk psychology concepts to keep and what to discard, thus making simply minor adjustments to the view.
Churchland’s Reply. Fair enough. Perhaps Revisionary Materialism is called for instead of Eliminative Materialism. But time and research will tell. And Churchland is betting that we will be closer to Elimination rather than Revision.
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