<< 前へ │ 次へ >>

# Discussion about Epiphenomenalism Epiphenomenalism is the view in philosophy of mind. According to this theory, physical events have mental effects, but mental events have no effects of any kind. In other words, the subjective mind does exist but it is not efficacious. This is a radical idea because it denies the concept that the mind has any control over the body, or even any ability to cause an action in the world. According to epiphenomenalists, mental events are just epiphenomena; they are side-effects or by-products of physical processes in the nervous system. On appearance, a man might be no different from a robot or a zombie which does not have qualia, subjective experiences, because his conscious mind does not affect his behaviour. The conscious accompaniments of brain activity are causally impotent. Mind-mind causation as well as mind-body causation is impossible. Because this theory seems to be implausible and unacceptable for many philosophers, they have attacked it more often than they have defended it. We will look at some arguments against epiphenomenalism and how epiphenomenalists have replied on each of them. First of all, because epiphenomenalism asserts, as we have already seen in the introduction, that our mind is epiphenomena of the brain and completely impotent; nevertheless, many say this view is deeply counterintuitive. The view of the fact that, for common people, it is evident that if they shout sometimes because they are in pain, or that if they smile to someone because they feel sympathy towards that person. So common people do not intuitively accept the view. Taylor (1963) asserts, “epiphenomenalism is absurd; it is just plain obvious that our pains, our thoughts, and our feelings make a difference to our [physical] behavior: it is impossible to believe that all our behavior could be just as it is even if there were no pains, thoughts, or feelings.” エピフェノメナリズムによると意識は単なるエピフェノメナ(付随現象)であって、肉体になんら影響をもたない。 However, epiphenomenalists can make the following replies, though this argument may have been more persuasive than any other. One response is that though epiphenomenalism seems incoherent and unacceptable, there cannot be any reason for rejecting it. To be specific, Jackson, one of the defenders of epiphenomenalism, states that “our evidence reveals only regular connections between phenomenal states and actions, so that certain sorts of experience are typically followed by certain sorts of action”(Jackson,1982). Therefore, following this constant conjunction, we should believe that the relationship between consciousness and reports about consciousness seems to be something of a lucky coincidence. But in fact, it is compatible with the absence of a causal connection. いくらこれが不整合で反直感的であろうとも、合理的な反駁は不可能。 The other theory that defends epiphenomenalism from the intuitive objection is proposed by Robinson (2003). It is often said that pains cause withdrawals of affected parts of the body. However, in a case of touching a hot stove, it can be observed that the affected part is withdrawn before the pain is felt. These cases cannot show that pain never causes withdrawals, but they do show that pain is not necessary as a cause of withdrawals. 反射的な行動は痛みを感じる前に、行われる。 The second objection to epiphenomenalism is based on evolution theory, which is initially suggested by William James (1879). According to him, the properties of consciousness indicate its causal efficacy. First of all consciousness probably becomes more complex and intense in the course of animal evolution. In this sense it is similar to a physical organ. Secondly, consciousness would be a kind of selective agency, an instrument to make decisions with. Thirdly, the nervous systems which get more complex at every stage of evolution, do not only seem to adapt better every time, and to get more flexible each time, but also they seem to get more unstable with every evolutionary step. It is for this reason that consciousness would have originated, following James, as it makes choices, and thus prevents the brain from being lost in chaos. This is due among other reasons to the fact that only consciousness has something to choose, matters have no ideals to pursue. Thus consciousness raises the probability of the maintenance of biological life. On this point, James reasons as follows: “This plausible image offers a justification of the existence of consciousness. If consciousness does not matter, why would it ever have originated during evolution?”(James,1879) Jackson (1982) replies to the evolutionary argument as it is that its proponents do not realize enough that not all individual parts of an organism need to be functional from the point of view of evolution theory. A bear may, for example, have a thick and warm skin which is also very heavy. The warmth of the skin contributes to the bear's survival, but the weight does not. The weight is an inevitable epiphenomenon of the fact that the skin is thick and warm. Thus it is well conceivable that something inevitably originates as a consequence of a certain organization of genes without it having any importance for evolution itself. Therefore, it is incorrect to sustain that epiphenomenalism would inevitably contradict evolution theory. It is not necessary for consciousness to have a positive effect in order to be conserved as a possible effect of evolution, but exclusively that it would not affect the probability of survival and reproduction in a negative way. This is precisely what is the case according to epiphenomenalism: consciousness does not have any impact on anything, neither positive nor negative. The third objection and the most powerful reason for rejecting epiphenomenalism is the view that it is incompatible with knowledge of our own minds. The argument that is given to support the destructive claims is that knowledge of one's mental events requires that these events cause one's knowledge, but epiphenomenalism denies physical effects of mental events. So, either we cannot know our own mental events, or our knowledge of them cannot be what is causing the plainly physical event of our saying something about our mental events. Thus, let us imagine a man who is an epiphenomenalist, and he utters "I am in pain." He is committed to the view that the pain does not cause the utterance. But then, it seems, he would be making the same utterance whether or not a pain were occurring. If this is so, then his testimonies about his own pains are worthless to both us and him. They cannot be taken to represent any knowledge about pains on his part (if his epiphenomenalist view is true). In fact, on an epiphenomenalist view, all the arguments for epiphenomenalism and rebuttals to counterarguments we have reviewed might be given even if we were all zombies. この理論に従うと、我々はゾンビと何ら変わらないことになる。 A response can be found in Chalmers (1996). His property-dualistic view holds that there is more to a person than just a brain and a body. It allows for persons to be directly acquainted with experiences, and it is this direct acquaintance, rather than any causal relation, that justifies our beliefs about experiences. On this view, experiences are partially constitutive of beliefs about experiences, and "the justification of my belief [about experiences] accrues not just in virtue of my physical features but in virtue of some of my non-physical features -- namely the experiences themselves" (Chalmers, 1996). In supplying non-causal relations to support the claim to knowledge of experiences, this view disconnects the knowledge question from the question of how things stand causally, and thus avoids the self-stultification argument. In addition to the problems above, epiphenomenalism implies that we do not know that others have mental states because epiphenomenalism denies the connection between mental events and behavioral effects. Epiphenomenalists can reply to it as it is natural to say that I know that I have mental states because I experience them directly. But how can I justify my belief that others have them? The simple version of the argument from analogy says that I can extrapolate from my own case. I know that certain of my mental states are correlated with certain pieces of behavior, and so I infer that similar behavior in others is also accompanied by similar mental states. However, many hold that this is a weak argument because it is induction from one instance, namely, my own. The argument is stronger if it is not a simple induction but an argument to the best explanation. I seem to know from my own case that mental events can be the explanation of behavior, and I know of no other candidate explanation for typical human behavior, so I postulate the same explanation for the behavior of others. But if epiphenomenalism is true, my mental states do not explain my behavior and there is a physical explanation for the behavior of others. It is explanatorily redundant to postulate such states for others. In conclusion, as having seen, epiphenomenalism has been criticised by several philosophers because it is a counterintuitive view that many find difficult to accept. At the same time, we look at no one could completely deny the theory. Chalmers states “Inelegance and counterintuitiveness are better than incoherence”. Actually, epiphenomenalism is an answer to the question of the causal influence of the mind or consciousness on reality. The answer is that the mind does not exercise any influence. The mind is always only an effect and never a cause. As such, epiphenomenalism may be classified within so-called dualism physicalism. --- ## 注 --- ## 参考文献

<< 前へ │ 次へ >> │ 一番上に戻る