666

A different dualistic approach accepts the causal closure of physics by holding that phenomenal properties have no causal influence on the physical world (Campbell 1970, Huxley 1874, Jackson 1982, and W.S. Robinson 1988, 2004).  Thus, any physical effect, like a bodily behavior, will have a fully physical cause.  Phenomenal properties merely accompany causally efficacious physical properties, but they are not involved in making the behavior happen.  Phenomenal properties, on this view, may be lawfully correlated with physical properties, thus assuring that whenever a brain event of a particular type occurs, a phenomenal property of a particular type occurs.  For example, it may be that bodily damage causes activity in the amygdala, which in turn causes pain-appropriate behavior like screaming or cringing.   The activity in the amygdala will also cause the tokening of phenomenal pain properties.  But these properties are out of the causal chain leading to the behavior.  They are like the activity of a steam whistle relative to the causal power of the steam engine moving a train’s wheels.

Such a view has no obvious logical flaw, but it is in strong conflict with our ordinary notions of how conscious states are related to behavior.  It is extremely intuitive that our pains at times cause us to scream or cringe.  But on the epiphenomenalist view, that cannot be the case.  What’s more, our knowledge of our conscious states cannot be caused by the phenomenal qualities of our experiences.  On the epiphenomenalist view, my knowledge that I’m in pain is not caused by the pain itself.  This, too, seems absurd:  surely, the feeling of pain is causally implicated in my knowledge of that pain!  But the epiphenomenalist can simply bite the bullet here and reject the commonsense picture.  We often discover odd things when we engage in serious investigation, and this may be one of them.  Denying commonsense intuition is better than denying a basic scientific principle like causal closure, according to epiphenomenalists.  And it may be that experimental results in the sciences undermine the causal efficacy of consciousness as well, so this is not so outrageous a claim (See Libet, 2004; Wegner 2002, for example).  Further, the epiphenomenalist can deny that we need a causal theory of first-person knowledge.  It may be that our knowledge of our conscious states is achieved by a unique kind of noncausal acquaintance.  Or maybe merely having the phenomenal states is enough for us to know of them—our knowledge of consciousness may be constituted by phenomenal states, rather than caused by them.  Knowledge of causation is a difficult philosophical area in general, so it may reasonable to offer alternatives to the causal theory in this context.  But despite these possibilities, epiphenomenalism remains a difficult view to embrace because of its strongly counterintuitive nature.