The concept of substance leads to a materialist aspect of the mind. I speak instead of the spiritual existence of the self without mentioning any 'su… - John Eccles

The materialist critics argue that insuperable difficulties are encountered by the hypothesis that immaterial mental events can act in any way on material structures such as neurons. Such a presumed action is alleged to be incompatible with the conservation laws of physics, in particular of the first law of thermodynamics. This objection would certainly be sustained by nineteenth century physicists, and by neuroscientists and philosophers who are still ideologically in the physics of the nineteenth century, not recognizing the revolution wrought by quantum physicists in the twentieth century.

The hypothesis has been proposed that all mental events and experiences, in fact the whole of the outer and inner sensory experiences, are a composite of elemental or unitary mental experiences at all levels of intensity. Each of these mental units is reciprocally linked in some unitary manner to a dendron … Appropriately we name these proposed mental units 'psychons.' Psychons are not perceptual paths to experiences. They are the experiences in all their diversity and uniqueness. There could be millions of psychons each linked uniquely to the millions of dendrons. It is hypothesized that it is the very nature of psychons to link together in providing a unified experience.

In order that a "self" may exist there must be some continuity of mental experiences and, particularly, continuity bridging gaps of unconsciousness. For example, the continuity of our "self" is resumed after sleep, anaesthesia, and the temporary amnesias of concussion and convulsions.