Dear Jim,Making use of ideas of Charles Martin's, but not following all his claims, my feeling is that although your argument must be right in one reading, it may be wrong to attribute causal powers to qualia.

An electron has a causal power to repel other negatively charge entities. However, if we consider what an electron 'might be like' either  to another electron or to a proton it seems reasonable to think the 'qualia' that might be involved would be different - sort of opposite. Similarly, everything we know about the way humans experience things tells us that the experience will be dependent both on the causal powers of things going on in the outside world and the 'sensitivity' of the sensory apparatus to these powers. (If you come more proximal and talk of causal powers of inputs to synapses the argument remains.) Using Martin's terms (not quite his final take) a quale ought to be a manifestation of what the dispositional powers of something ought to seem like to a subject and this seeming will be determined just as much by the dispositional powers of the subject to be sensitive to the other powers. Thus qualia in this view would not have causal powers in the way that these are attributed to 'things'. Qualia would be manifestations to a subject (this is not strictly Martin's interpretation) of the co-disposition of one thing interacting with the co-disposition of that subject. This would be like 'pulling' or 'pushing' rather than 'negative charge'. Qualia would be inescapable elements of the acting out of a causal relation, but if we were to ask what their causal powers are we would find that there cannot be a meaningful answer. It would be a bit like asking 'do electrons pull or push - period?'. Thus there is every reason for it to seem that qualia cannot cause anything in terms of the laws of physics, but that need not mean that they are not part of the causal process.

Jo E