Hence, if our theory is true it follows that man will find a quality of being in himself which he finds immediately in no other system which he knows. The answer is in the affirmative. Man finds something in himself which he discovers immediately in no other creature or object. It is consciousness. Moreover, when one cuts off or abstracts from all physical and formal effects upon oneself, and turns back into the pure experience of one's own being, what does one find but the very definition of the psychical which we have given.
Nothing remains but bare indeterminate experience.
It is of this that the mystic speaks. And it is precisely because it is experienced yet indeterminate, that he asserts it to be the most certain and intense of realities, yet cannot transmit it to others. Such is the nature of the psychical. It is incommensurable and untransmissible. But the physical and formal properties of an electron or of the macroscopic atom are different from those of man.