Cair Paravel. He tells him he will one day rule as High King in that castle, because he is older than his siblings.
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Walt Whitman asks this question because he wants the reader to think about the question. In this, he celebrates the idea of being who he is, as a human. What he means in the statement is that he is contradictory, which is like doing one thing but saying the other. In other words, he is a man of inconsistency, which is human nature in itself.