Sentence:  The <WSD>self</WSD>, the I, is recognized in every act of intelligence as the subject to which that act belongs. It is I that perceive, I that imagine, I that remember, I that attend, I that compare, I that feel, I that will, I that am conscious. 
Meaning of the word marked with <WSD> tags:  An individual person as the object of his own reflective consciousness (plural selves).