Think about it – a cause of consciousness. What does it mean? Does it mean that the cause is operative in the identification of itself? Or does it mean that the cause and effect work in some kind of relationship brought about by a difference occasioning an interaction?
But how are we to identify a difference without a point of comparison that is particular to the nature of consciousness? And how can the observation of parallel changes in the operations of consciousness and its physical support processes prove sufficient to explain any differences or show that they are one and the same thing?