Epiphenomenalism

Epiphenomenalism is the view in philosophy of mind according to which physical events have mental effects, but mental events have no effects of any kind. 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. Human experience is present, but inert.

Explanation
Imagine both Pierre and a robot eating a candy bar. Unlike the robot, Pierre is conscious of eating the candy bar while the behavior is under way. This subjective experience is often called a quale (plural qualia), and it describes the private "raw feel" or the subjective "what-it-is-like" that is the inner accompaniment of any observable behavior. Pierre and the robot can both be doing the same thing, but only Pierre has the inner conscious accompaniment.

According to epiphenomenalism, mental events like Pierre's pleasurable experience -- or at any rate their distinctive qualia -- are just epiphenomena; they are side-effects or by-products of physical processes in the nervous system. Upon appearance, Pierre might as well be a robot or a zombie, because his conscious mind does not affect his behavior. If Pierre takes a second bite, it is not caused by his pleasure at the first. The conscious accompaniments of brain activity are causally impotent. Mind-mind causation as well as mind-body causation are impossible, according to epiphenomenalism: When Pierre thinks, "That was so good I will take another bite," his thought is not caused by the preceding pleasure.

A good way to think of consciousness under epiphenomanlism is the foam in a glass of beer. Foam serves no purpose and is sort of immaterial. It is the mere stirring and mixing of chemicals in the beer which gives rise to foam. It dissipates soon, but there are always more bubbles on their way up. Similarly, consciousness has no function and is the accidental result of brain activity. Things rise to conscious experience only after they have been perceived by the brain, including the experience of decision-making, which is a deterministic event. Choice is something the brain performs certain formulas on and choosing is the apparently "magical" result of that computation. Free will is thus an illusion.

Background
Metaphysical epiphenomenalism has a niche among methodological or scientific behaviorism. In the early 1900's scientific behaviorists such as Ivan Pavlov, John B. Watson, and B.F. Skinner began the attempt to uncover laws describing the relationship between stimuli and responses, without reference to anything inner. These scientific behaviorists could have adopted eliminativism or mental fictionalism, positions which deny that the mind exists, but epiphenomenalism enables a behaviourist to allow for the existence of mind. By the 1960's, scientific behaviourism met substantial difficulties and eventually gave way to the cognitive revolution. Participants in that revolution such as Jerry Fodor insist upon the causal efficacy of mind. Fodor even speaks of "epiphobia" -- fear that one is becoming an epiphenomenalist.

Critical responses
The philosophical behaviorists (as opposed to scientific behaviourists) would reject epiphenomenalism on the grounds that it is, in Gilbert Ryle's phrase, a "category mistake." Just as there is no Cartesian "ghost in the machine", there are no ghostly events that accompany behavior in an inner theater. Consciousness belongs not to the category of objects of reference, but rather to the category of ways of doing things. To be attentive is to do things with focus and care, not for something to be happening in the ghostly theater that Ryle lampooned as a dualist dogma.

Functionalists chart a different course, accepting that there is a system of mental events mediating stimulus and response, but asserting that this system is "topic neutral" and capable of being realized in various ways. The topic neutrality of the mind implies denial of epiphenomenalism, which, as a kind of property dualism, fixes consciousness as a non-neutral, non-physical topic.

Eliminative materialists on the other hand assert that our concept of mind aims to fix reference to a non-physical topic, so they disagree with the philosophical behaviorist analysis, as well as the functionalist analysis. Eliminative materialism holds however that this dualistic aim of "folk psychology" is a fatal error built into mental concepts, no doubt partially because of the influence of Cartesian ideas on word meanings and the way we folk think about ourselves. So it would be better to eliminate the concept of mind, and concepts implicated in it such as desire and belief, in favor of an emerging neurocomputational account. (A more moderate eliminativist position would run what J. L. Mackie called an error theory, stripping false beliefs away from the problematic concepts but not eliminating them, leaving intact a legitimate core of meaning.)

Arguments Against
I. The most common criticism of epiphenomenalism is that it feels like the mind has influence. For example it is possible to imagine the most bizarre body gesture with your mind and then to do it. William James urged something like this criticism against epiphenomenalism, which he named "Automatism." However inadequate our ideas of causal efficacy may be, we are less wide of the mark when we say that our ideas and feelings have it, than the Automatists are when they say they haven't it. As in the night all cats are gray, so in the darkness of metaphysical criticism all causes are obscure. But one has no right to pull the pall over the psychic half of the subject only, as the automatists do, and to say that that causation is unintelligible, whilst in the same breath one dogmatizes about material causation as if Hume, Kant, and Lotze had never been born. One cannot thus blow hot and cold. One must be impartially naif or impartially critical. If the latter, the reconstruction must be thorough-going or 'metaphysical,' and will probably preserve the common-sense view that ideas are forces, in some translated form. But Psychology is a mere natural science, accepting certain terms uncritically as her data, and stopping short of metaphysical reconstruction. Like physics, she must be naïve; and if she finds that in her very peculiar field of study ideas seem to be causes, she had better continue to talk of them as such. She gains absolutely nothing by a breach with common-sense in this matter, and she loses, to say the least, all naturalness of speech. [The Principles of Psychology, Chapter V, "The Automaton Theory"] II. One particularly potent problem is that the presence of the theory of epiphenomenalism seems to contradict the very idea. Most people feel that thinking is a mental process, so how could someone ever express the idea of epiphenomenalism? It would be impossible, as this "expressing" would require the banned connection between mind and behavior. If epiphenomenalism is true, then its truth is ineffable. So in the example above, Pierre cannot convey his pleasure.