What important theme of realism is reflected in these lines from “Song of Myself” by Walt Whitman?

And as to you Corpse I think you are good manure, but that does not offend me, I smell the
white roses sweet-scented and growing,
I reach to the leafy lips, I reach to the polish'd breasts of melons.

the beauty of nature and human life
the beautiful and harsh realities of life
the harsh realities of a cruel world
the mystery of the food chain in nature

Question

What important theme of realism is reflected in these lines from “Song of Myself” by Walt Whitman?

And as to you Corpse I think you are good manure, but that does not offend me, I smell the 
white roses sweet-scented and growing,
I reach to the leafy lips, I reach to the polish'd breasts of melons.

the beauty of nature and human life
the beautiful and harsh realities of life
the harsh realities of a cruel world
the mystery of the food chain in nature

anonymous · Answer

W.W objectively explores man's relationship with nature. The purpose of human endeavor, itself shaped by nature, hardly influences nature. The verisimilitude (in diction and layout) reflects upon this detachment of man from nature and the ensuing clash of ever changing desire (of man) with the immutable (nature's conduct). The cycle of construction, birth, life, death and deconstruction is what lies at the heart of these words. The way of nature,  eliciting curiosity, nourishing it and then withdrawing the truth (of life and its purpose), baffles humanity and eventually, like all things at their end, consumes it.