Whatever becomes an object to consciousness cannot be the conscious self which notes it as an object. Every thought, therefore, even the thought of the person, is such an object. The real self must consequently inhere in a consciousness which transcends the person and which can be nothing other than pure consciousness itself. The keen insight of the Chinese sages perceived this and hence they used the term Ko, which means "to be aware," as representing the transcendental knowledge of real being, and the same term, which also means "he who is aware," as representing a man like the Buddha who is possessed of such knowledge.
-- Notebooks Category 21: Mentalism > Chapter 5: The Key To the Spiritual World > # 185