The reason why one cannot see the soul is that it is the soul that sees all things, and the soul has to become two in order to see itself, and this can never be. As consciousness is realized by being conscious of something, and as intelligence is realized by the knowledge of things, so the existence of the soul can be proved by one's very existence. That part which exists in one, or which makes one existent, that part which sees, conceives, perceives, and is conscious of all things and yet above all things is the soul.