Putnam's best-known work concerns philosophy of mind. His most noted original contributions to that field came in several key papers published in the late 1960s that set out the hypothesis of multiple realizability. In these papers, Putnam argues that, contrary to the famous claim of the type-identity theory, it is not necessarily true that "Pain is identical to C-fibre firing." Pain, according to Putnam's papers, may correspond to utterly different physical states of the nervous system in different organisms, and yet they all experience the same mental state of "being in pain".
Putnam cited examples from the animal kingdom to illustrate his thesis. He asked whether it was likely that the brain structures of diverse types of animals realize pain, or other mental states, the same way. If they do not share the same brain structures, they cannot share the same mental states and properties. The answer to this puzzle had to be that mental states were realized by different physical states in different species. Putnam then took his argument a step further, asking about such things as the nervous systems of alien beings, artificially intelligent robots and other silicon-based life forms. These hypothetical entities, he contended, should not be considered incapable of experiencing pain just because they lack the same neurochemistry as humans. Putnam concluded that type-identity theorists had been making an "ambitious" and "highly implausible" conjecture which could be disproven with one example of multiple realizability. This argument is sometimes referred to as the "likelihood argument".
Putnam formulated a complementary argument based on what he called "functional isomorphism". He defined the concept in these terms: "Two systems are functionally isomorphic if 'there is a correspondence between the states of one and the states of the other that preserves functional relations'." In the case of computers, two machines are functionally isomorphic if and only if the sequential relations among states in the first are exactly mirrored by the sequential relations among states in the other. Therefore, a computer made out of silicon chips and a computer made out of cogs and wheels can be functionally isomorphic but constitutionally diverse. Functional isomorphism implies multiple realizability. This argument is sometimes referred to as an "a priori argument".
Jerry Fodor, Putnam, and others noted that, along with being an effective argument against type-identity theories, multiple realizability implies that any low-level explanation of higher-level mental phenomena is insufficiently abstract and general. Functionalism, which identifies mental kinds with functional kinds that are characterized exclusively in terms of causes and effects, abstracts from the level of microphysics, and therefore seemed to be a better explanation of the relation between mind and body. In fact, there are many functional kinds, such as mousetraps, software and bookshelves, which are multiply realized at the physical level.
Frankenstein wrote:Multi-realizability? Are you talking about functionalism, and how brain states may be analogous to how circuit boards work, or even a system of pipes and water arranged in a complex fashion?
Frankenstein wrote:Which book? I have some of his stuff already. The guy is a genius. However, I don't see ho functionalism, even in tandem with fuzzy logic, will give rise to consciousness. It will give rise to better, more convincing zombies though .
Maybe I'm just hung up on the whole, machine idea, and how machines, consciously, are absolutely dark inside-- that is, not thinking things in the since that we are. Do they know what it is to "play" a game, to never want it to end, like a game of chess or life? Do they "understand" or is it just following a function that a human programmed it to do?
Having one substance working on itself certainly seems to fix the explanatory gap, however, if common sense is about the best we have, and thoughts ideas, sensations really do seem different from physical stuff, such as tables cars and chairs, then how can we be sure there isn't two distinct substances?
Therefore, a computer made out of silicon chips and a computer made out of cogs and wheels can be functionally isomorphic but constitutionally diverse. Functional isomorphism implies multiple realizability. This argument is sometimes referred to as an "a priori argument".
Frankenstein wrote:Hello everyone. I wrote a paper on qualia, here it is. I'm doing a little presentation in front of some people I deem important. Anyone care to ask me about qualia as if it were a Q and A session? This will be good practice for me, if anyone cares to. Below is the paper I wrote. Qualia is suggested in the third paragraph. It's controversial because it seems to lie outside what physics can describe, and may even lie outside physics altogether, but that's taking a dualist position. Qualia are sensations/perceptions such as the redness of red, pain, sweetness etc.. Please ask questions, Ill do my best to answer them!!!
Mary, Quite Contrary: Consciousness Unexplained
What is the ultimate nature of reality? In Philosophy of mind, there are many positions regarding what has real being. On a commonsense level, dualism seems to be the reality. Thoughts, beliefs, and qualia really do seem to be different from tables, apples, and automobiles; therefore, according to dualists, there are two types of stuff furnishing reality. However, the gap that bridges the mind and body remains a mystery-- no one has yet explained how they interest. To put it another way, how does a physical brain state, consisting of neurons firings, cause the associated mental event, that just is a feeling pain, or any feeling at all?
Many philosophers have argued that the physical sciences show the way to the answer. On this view, the unparalleled successes of scientific predictions and explanation justify the belief that all reality is physical. One expression of this physicalist account may be found in cognitive neuroscience. To explain vision, neuroscientists will point out that the first physiological response to light is biochemical, occurring in the photoreceptor cells in our eyes. From there, as electrical patterns, the signal travels to the back of the brain, into the occipital lobe, and subsequently to other areas. The physicalist will assert that conscious experiences are actually nothing other than a property of neural events just described.
Many other philosophers question whether science can provide an account of everything that exists. We do not see electrical patterns-- we see colors, cars, pedestals, and people. How is this possible? “Qualia” is the term currently used by some philosophers to refer to conscious phenomena they believe lying outside the scope of scientific explanation. The redness of red, the small of a rose, and the feeling of pain, they claim, are nothing like atoms, wave-length, quarks and gluons, or any of the other phenomenon which form the subject matter of the physical sciences. In this paper I will argue that this view is correct, and that there are phenomena that can never be accounted for from the scientific perspective.
Frank Jackson's “Mary Problem” gives a clear, concise contemporary argument for the existence of qualia, which he claims, are not physical. About a woman raised in a black-and-white environment, this is the Mary Problem:
Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room, with a black and white television monitor. She specializes in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like 'red', 'blue' and so on. She discovers, for example, just which wave-length combinations from the sky stimulate the retina, and exactly how this produced vie the central nervous system the contraction of the vocal chords and expulsion of air from the lungs that result in the uttering of the sentence 'the sky is blue'. (Quoted in Heil p.765)
One day she leaves the lab and walks into the sunlit world, and she experiences color! In the view of those who believe in qualia, this means that she learns something new that the study of physics could not tell her. Therefore, Jackson claims, the Mary problem shows that physics, in the black and white room, does not account for all of reality. All that physics could have taught Mary is what we typically refer to as objective descriptions of the physical world, which can only describe color as radiation wave-lengths that hit the retina and send patterns of electrical signals to the brain. What is missing in the neuroscientific equation is the actual conscious experience of color seen.
The philosopher and neuroscientist, Daniel Dennett, believes that the problem of qualia should be dispelled. To make his case, Dennett argues that we ought to focus on a premise in Frank Jackson's “Mary Problem” argument. If we recall, Jackson says that Mary knows, “all the physical information...” (765). However, Dennett asserts, if Mary knew all the physical information there is to know about color, then she would not learn anything about color, when stepping outside. He states boldly: “she knows everything-- absolutely everything--... about the physical causes and effects of color vision” (399). Therefore, Dennett claims that, Mary would have predictive power regarding events in the physical world, since everything to be learned is ultimately describable in physical terms. According to Dennett’s critique, “[Mary would know] exactly what physical impression a yellow object... would make on [her] nervous system” (Dennett 399-400). He concludes, “So the only task that remains is for her to figure out a way of identifying the relevant neurophysiological effects “from the inside” (p.400). By figuring out that some color isn’t yellow or red, from knowing the physical reaction that yellow would have on the nervous system, Dennett believes, she would then be able to open the flood gates to the color spectrum—before exiting the black and white room. Dennett finally concludes that the existence of color as “qualia” is null and void, for there is no actual objective evidence of it, only our own reports of allegedly private perceptual experiences.
Let us review Dennett's argument further. Jackson is stating that physics is not complete because there is a subjective aspect to our consciousness. For this part, Dennett wants to show that physics can describe everything that truly exists. The first way in which Dennett's argument falls short is in its emphasis on knowing by description rather than on knowing by the actual experience. For supporters of the Mary Problem, even though Mary presumably knows all that physics conveys, she cannot know what it is to see the color red when she leaves her black and white room. As of yet, no one knows how physical brain-states interact with events characterized as “mental”. It may be the case that all physics can ever do is describe phenomena, external to our mental states. This leaves a problem for physicalists, like Dennett, for how does one describe the sensation of color to one who hasn't seen the redness of red? As a supporter of the Mary Problem myself, I claim that It's finally left to our conscious experience to actually sense the phenomenon, called qualia, like the feeling of a pain or perception of color.
Secondly, without the actual prior experience of color, Mary has no way to associate the relevant neurophysiological events with the qualia experienced. Dennett's solution for Mary is merely to have her study neurophysiological effects on her own brain. Neurophysiological effects are one thing, but now Dennett wants to suppose color is a neurophysiological effect that is reducible to physical terms, but what is relevant is that the qualia actually experienced are qualitatively different, not quantifiable or reducible to the physical sciences. And since these are different in kind, rather than in degrees, Dennett will hit a road block when attempting to reduce something not reducible in physical terms. To illustrate the issue, using an example from Leibniz: “imagine a brain that is blown up to the size of a building. Upon entering, all we see are [physical] parts working on each other; nowhere do we find anything that explains or shows perceptions [known as qualia]” (Leibniz P.50). So, Dennett's argument basically restates the issue: how is Mary going to associate the relevant brain response with the color if she hasn't seen the color prior to the neurophysiological response? Viewing the brain's physical makeup in motion will not explain color as seen by Mary when looking out into the colored world. Therefore, Dennett's solution for Mary-- which is studying neurophysiological events functionally-- still presents Mary with a gap.
At every corner we turn we again bump into this explanatory gap, between mind and matter. Dennett's solution, which is opposed to common sense, is ultimately to deny that we have the subjective sensations other philosophers call “qualia”. While Dennett is correct in claiming that humans can't "objectively” prove the existence of qualia-- I can't help but feel Dennett is missing an essential ingredient of consciousness, if qualia are left out. To dilate on this, is it not self-refuting to deny one's own sensations? To have perception, at a bare minimum, means that one knows what it is like to be conscious.
Dennett is not alone in his view of subjective experience. As a result of the "Enlightenment", one of the beliefs some people do hold is that the physical world makes up all that is reality. However, we would do well to acknowledge that if we set out to describe all of reality, using a method designed to discover only what is physical, then our conclusions must be that everything is physical. On this model, of course physics is complete! I am not here denying the success of scientific achievement, I am merely pointing out this limitation. A scientific method, limited to objectivity, has no capacity for discerning what lay beyond the range of scientific description. Daniel Dennett shows us a picture of a machine, but a machine is, as Leibniz says, simply a set of physical parts working on each other. Would this machine smell coffee, or a burning sensation if spilled on the machines lap? No matter how many pieces we add to the machine, it seems as if it won't welcome qualia, unless it could have that extra ingredient, conscious experience.
Ierrellus wrote:Thanks for the first positive thing you ever said about me. Yes, the NSDD needs to be devised. We know about consciousness now only from brain probes and brain disorders. Many are still looking for the image inside the computer without considering how the computer produces images. For those who claim to be something other than neurons can produce, there exists no quale, no "I", without neuronal and genetic hardwire.
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