This is a bit hard to argue with since (shades of Berkeley) we don't have much access to a world devoid of consciousness.

However, there are some serious difficulties:

The whole proposal requires putting people at the center of the existence of the universe. How does that square with everything else we know, e.g. evolution? The world we see shows overwhelming evidence of having once been free of consciousness. Were the laws of physics entirely different then? Who (bacterium, amoeba, monkey, Wigner,…) was finally conscious enough to collapse the wave function and make positions, etc of particles exist? Just how did Wigner get there before anything had positions?

While there is no evidence that consciousness plays some role distinct from any other phenomena involving macroscopic masses and times, it is worth taking a closer look at consciousness. In so doing, we will be able to determine why the Chalmers argument is not quite right.

Consciousness

What do we mean by consciousness? Conscious experience is a widespread phenomena. Whenever, we say that `I really like that line of poetry,' or `ouch that hurts' or 'I feel uncomfortable when you stand that close to me,' we are talking about mental states. Mental states (not to be confused necessarily with brain states) are what we mean by consciousness. Notice that statements about one's conscious state are framed from the first person, that is, there is a perspective. Consider reading a line of poetry. A physical act occurs, namely your eyes scan the line. However, if you say after you read the line, `ah that line really moved me', you are expressing more than what happened physically. You are talking about the mental state that you experienced after (or while ) you read the line of poetry. You are expressing the subjective aspect of the experience. A subjective component to an experience is typically unique. Only you can have the particular reaction that you had. While many might feel moved by the same line, your particular feeling of being moved is truly your own. No one else will feel particularly the same way. Hence, consciousness generally refers to what is left over once we subtract the objective (or physical) aspect of an experience. An equivalent paraphrase of what consciousness is, is that it is the qualitative aspect of an experience. An organism has consciousness experiences if there is something that it is like to be that organism. This is the standard definition of consciousness put forth in the essay by T. Nagel, ``What is it like to be a bat''. We introduce the term qualia to refer to the general class of subjective components that accompany any experience, feelings of glee, joy, love, dejection, etc. All of these are subjective and hence are left over once we subtract the fact that some physical act occurred. The hard problem of consciousness is to explain experience. For example if someone were to say that although you have determined the crystal structure of an amino acid, you have not answered the question of what it is like to be an amino acid or how is it an amino acid, they would be nonsensical. There is nothing that it is like to be an amino acid. However, one could say that while you have offered a physical account of an experience, you still have not explained what it is like to have that experience, that instinct would be correct because the experience is first person. Qualia are not physical things. There are many who would disagree that qualia are anything at all and really distinct from the physical. Herein lies the problem with consciousness: From where does the subjective component of an experience arise? Is it distinct from the physical stuff that causes the mental event. Is it reducible to something purely physical, that is, so many neurons firing, for example? If the mental events have physical causes and effects, then why are we not able to strip away the mental talk and describe mental events purely in objective physical terms? Perhaps consciousness is irreducible and hence wholly distinct from physical phenomena? Descartes was really the first to say anything interesting on this problem. His argument was that when I am thinking, I am not necessarily aware of anything physical that is going on in my brain. Hence, there is no necessary connection between the physical and the mental, and Cartesian dualism was borne. But dualism does not seem to be tenable. So the central problem in consciousness is that there seems to be some sort of disconnect(that is, an explanatory gap with no apparent bridge) between a physical description of a mental state and the actual mental state. That is, if I were to look in someone's head, I do not see a desire to eat ice cream or thoughts of Marxism or minature pictures of the Mona Lisa. I see wiring, biochemistry, and living tissue. In this sense, the mind-body problem is fundamentally different from the stomach-digestion problem, or the lung-respiration problem. No phenomenal talk is necessary to describe either of these problems. However, once we talk of consciousness, a physical description seems to be entirely insufficient. I will put off the subject of physicalism proper (that is mental states are identical to physical states and that is all there is to the problem) until next class and focus primarily on the computer model of mind--that is, functionalism.

Epiphenomenalism

This view purports that mental phenomena might be real alright but mental events cannot cause physical events. This really does not seem to correspond to our commonplace notion of the relation between the mental and the physical. However, the epiphenomenalists do seem to have a point. On some level, one can argue that physical stuff has physical causes. In fact, the only facts that follow necessarily from physical facts are other physical facts. But what about cases in which mental desires and states seem to affect our behaviour. Consider, for example, the real but fuzzy notion of personal space. We have all encountered someone, typically when we travel to a foreign country, who we do not know all that well but stands uncomfortably close to us. Our natural response is to take a step back. But they take a step forward. This illustrates two things: 1) mental states seem to cause behaviour and 2) the same physical situation can give rise to vastly different mental states. By the latter I mean that in the situation discussed above, one person feels uncomfortable and the other person feels totally at ease when standing 1.5 ft. from a total stranger. This reinforces the subjective aspect of an experience.

Behaviourism

On this view, mental states are just patterns of behavior and dispositions to behavior. By behavior we mean bodily movements. As a result on this view, there is really nothing mental about the mental: there is only the physical. Language is just noise coming out of your mouth. Here again, there can be no causal relationship between physical states and mental states. We have the intuitive notion that our beliefs cause us to act in certain ways. For example, the belief that an umbrella keeps you from getting wet makes you use it to shield yourself from the rain. Behaviourists must deny that this sort of chain of events takes place. They would say that my belief that it is raining will be manifested in carrying an umbrella only if I have a desire to stay dry. My desire to stay dry will manisfest itself in my carrying the umbrella only if I believe the umbrella will keep me dry. So to analyze why you took your umbrella, a behaviourist would have to bring in two subsidiary mental states. This process has no end.

Functionalism

The brain is a complicated computer program which generates lots of outputs. One of the outputs is simply conscious states. There are several ways in which the argument generally goes from here. One is the strong artificial intelligence stance. On this stance, it is argued that mental processes are identical to program processes of the computer. Hence, on this account, it is entirely possible to build a computer that thinks, has beliefs, has a sense of humor, and feels sad. Computer programs provide a list of formal commands. They provide a syntax. Do they provide a semantic? The answer is no. We associate with mental phenomena a semantic meaning. The following example of John Searle's illustrates the problem with the computer program view of mind. Consider that computer programmers have written a program that simulates the understanding of Chinese. By this I mean that questions are fed in and out pops reliably correct answers in Chinese. Let's assume that the computer's answers are as good as those of a native speaker of Chinese. The question arises does the computer understand Chinese in the way a native speaker of Chinese does? We can illustrate this with the following example. You are placed in a room in which there are a huge number of boxes containing Chinese characters. Lets assume you do not speak Chinese. Nonetheless, you are given a rule book for manipulating the Chinese characters. The instructions might say for example, take fish-shaped symbol out of basket 1 and place it next to sfsdfs-shaped symbol in basket 34 and so forth. Now suppose that someone keeps slipping cards with chinese characters under the door of the room and your rule book is expanded to tell you what Chinese symbols you must assemble to slip back under the door. It turns out that the cards being slipped under the door to you are questions in Chinese and the instructions for assembling the Chinese characters generate the answers to the questions. However, you do not know this. Now lets say you play in this room for quite some time and you become quite proficient in decoding the rules being slipped to you so that you can respond quite easily to the cards being slipped to you under the door. On the outside, it certainly looks like as if you know Chinese. The cards being slipped to you are all answered correctly with great rapidity. The question arises, do you understand Chinese. The answer is no. If the answer is no for you, then certainly the answer is no also for the digital computer. The reason is quite simple. The boxes of symbols are the database; the instructions being slipped to you are the computer program; the people giving you the questions and the answers are the programmers; and you are the computer. You are doing the assembling of the cards. Certainly no one would say that you know Chinese. Note you would pass a Turing test (that is, a passerby could not tell the difference between you and a native speaker). Likewise, one would also have to admit that neither does the computer. The reason is simple. You have no semantic knowledge. All you have is a syntax. The structure of this argument is quite simple: 1) programs are formal (syntactical) things, 2) minds have content (semantics) and 3) syntax is not sufficient for semantics. Hence, programs, however, elaborate are not minds. Note the question is not whether the whole system knows chinese--the question is does the component that is you (or the computer) know chinese. The answer is a resounding no. Hence, no amount of silicon chips put together by UI or MIT graduates can generate a computer that can have mental states. Here's another argument against the computational model of mind, also due to John Searle. Let us call those attributes of some x intrinsic attributes if they exist independent of an observer. All other features we refer to as being obsever-relative. Consider a steel chair. Steel is an intrisic property of the chair; however, that it is a chair is observer-relative. Consider computation. Is computation intrinsic or observer-relative? Let's say I am adding two numbers together. That I am adding two numbers together is a property of me independent of what anyone else thinks. Hence, that addition property is intrinsic. Now consider a digital computer. Is IBM's Deep Blue intrinsically a digital computer? Can anything intrinsically be a digital computer? The answer is no. A process is computational only relative to some observer or user who assigns a computational interpretation to it. So now the question is rephrased, ``can we assign a computational interpretion to the brain?'' The answer is that we can assign a computational stance to anything that looks to us as if it is computing. Hence, the `computer' model for mind is ambiguously formulated. There does not seem to be any clear sense of what is intended when one says the mind is a computer. To quote Wittgenstein, ``...machines cannot make claims ... of understanding.'' We can make such claims. Hence, there seems to be something obviously wrong with the functionalist approach in that it cannot account for the range of mental states we experience.