The unity between the individual and all living things.
Although the narrator of the poem speaks of himself, he is not Walt Whitman, or any other particular person for that matter. He is an Individual, who is at the center of his own universe; however, he is also all the individuals, as the essence of his being is the essence of humanity itself. The "self" of the poem is both singular and plural, individual and universal, earthly and cosmic.
[uncountable, countable] thought (of something/of doing something) an intention or a hope of doing something She had given up all thought of changing her job.