This statement by Mrs. Eddy appears on page 281 of the Christian Science textbook, Science and Health: "Divine Science contradicts the corporeal senses, rebukes mortal belief, and asks: What is the Ego, whence its origin and what its destiny?" In the next paragraph our Leader gives us the answer to this great question: "The one Ego, the one Mind or Spirit called God, is infinite individuality, which supplies all form and comeliness and which reflects reality and divinity in individual spiritual man and things."
Throughout her writings, Mrs. Eddy iterates and reiterates the immensely important fact that God is One and All, the infinite Being, or individuality, who is the very life, substance, and intelligence of His entire creation. To clarify this true sense of God as infinite individuality—conscious of Himself and of His universe—our Leader uses the term I, or Ego. Science reveals that God, the Ego. is alone Mind and that there is in real being no belief of minds many, no multiplicity of finite personalities who can say "I."
That there are no finite minds in no way contradicts the fact that the spiritual man is a distinct individuality. Rather, it clarifies the true nature of his identity by showing him to be the individualized expression of the one Ego, a specific, unique idea in Mind, which is God. Spiritual man, the Ego-man, is conscious of himself because he reflects God's self-knowledge; he has no underived self-awareness, for all knowing is the function of the one Ego.