The nature of consciousness is generally considered to be a big mystery. Is it the result of only physical, material processes, or is there something immaterial involved? Many experiments show a strong relationship between material and mental processes and a common viewpoint is that these correlations indicate that the material processes cause the mental processes. In other words, there is an implicit assumption that material processes are sufficient for generating the mind, that nothing else is needed beyond the material.

Of course, it’s well known that correlations do not mean causation – just because two items seem highly related, that does not mean that one must be causing the other. One reason for this is that the same thing can occur when one item is necessary for the system to function, even if it is not sufficient.