There may be no poem that so effectively embodies the concept of "nature poetry" than this one. This well-loved poem was controversial for some time after it was first published, because it contains imagery that is frankly sexual, and these sexual images are closely intertwined with the speaker's attitudes about nature. For example:
Urge and urge and urge,
Always the procreant urge of the world.
Out of the dimness opposite equals advance, always
substance and increase, always sex
Nature's imagery is connected via Whitman's words to the cycle of living and dying (harvest, decay, birth, fertility, etc.), but also to the range of emotional experiences (joy, wonder, love, sadness, etc.) that nature can inspire in human beings. This poetic work represents an attempt to engage deeply and completely with nature and to celebrate the human connection to the entire world of nature, via both work and recreation. Whitman creates powerful passages using descriptions of the natural world (plants, animals, landscapes, the elements, the seasons, etc.) that sustain these themes throughout.
The speaker/poet places himself in many different situations in nature (walking, hunting, lying in repose, etc.) and these moments form the opportunity for observation and insightful thought; in this way the poet seems to be suggesting that readers engage in such activity as well, in order to better understand the significance of nature in their own lives. He also praises the people who work closely with nature:
I am enamour'd of growing out-doors,
Of men that live among cattle or taste of the ocean or woods,
Of the builders and steerers of ships and the wielders of axes
and mauls, and the drivers of horses,
I can eat and sleep with them week in and week out.