If a materialist would stop to think about this mystery of the ultimate observer and if his thinking faculties were sufficiently sharpened, purified, and made capable of dealing with such an abstract subject, he would lose his materialism and become a mentalist. Let him ask himself who it is that speaks when he speaks about himself, what is this "I," this thing that bears his name? Since that which speaks and that which is spoken of cannot be the same but must be separate, then he would have to admit a further "I" behind the one that speaks about himself. He could go on analysing backwards in a never-ending series in this way. Each time the "I" would seem to have some other "I" to which it was an object and to which it could refer as the subject. The existence of his ego would be established in relativity, for it would seem he could move infinitely and indefinitely through this mystery of what is meant by "I." This is because the instrument which he is using for such analysis is the logical intellect, which would thus reveal to him its strict limitations.
Observing these limitations he would then have to ask himself whether or not it were possible to use a subtler instrument, and then mystical metaphysics would tell him: Yes, such a subtler instrument is available--it is your intuition. Cultivate this rightly, shun its counterfeit, subject your feelings to the philosophic discipline, and then practise meditation. You will find that your intuition will lead you back and back to the one element which is the final "I" and which directs every operation of the subconscious functions of the body, and which gives your personality its consciousness of existence. This "I" is non-physical; it is the inmost part of your mind. Understand this and you will necessarily have to give up materialism. You will become a votary of mentalism. Even more, the realization of this truth in actual experience makes you aware that the universe is friendly to you because you are intimately related to it. Your own mind grows out of the World-Mind. It is this relation which enables your mental nature to think and to know, your emotional nature to feel, and your physical body to act. Without it you would be dead in the fullest sense of the term. Everything inside of you, like everything outside you, changes; but this real Self never changes for it dwells in the kingdom of the World-Mind, the kingdom of heaven which is an everlasting one.
It is a phenomenal feat to understand Einstein's law of relativity as it applies to the physical world; but, after all, this understanding does not bring peace of mind or strength of life. It is quite another thing to understand the law of relativity as it applies to the inner Self and such understanding does bring these things. Our knowledge of physical relativity has led us to control of the atom, whose reward seems to be the likelihood that we shall destroy ourselves, but our knowledge of spiritual relativity leads us to control of the mind, whose reward is to save ourselves.
-- Notebooks Category 21: Mentalism > Chapter 5 : The Key To the Spiritual World > # 100
