Whitman's main literary device in Leaves of Grass (1855-87), which appears in nearly every section of the poem, is metaphor or simile, a characteristic of Whitman's poetic style. In addition, however, Whitman uses a variety of devices such as anthropomorphism, dialogue, monologue, syntactical inversion, onomatopoeia, and ellipsis (a favorite device of Emily Dickinson) to articulate his journey and transmutation from man to nature.
In Section 6, for example, Whitman begins with a child's question about the nature of grass and follows with his long metaphor-based monologue:
I guess it must be the flag of my disposition, out of hopeful green stuff woven./Or I guess it is the handkerchief of the Lord. . . . Or I guess it is the child itself, the produced babe of the vegetation.
These lines establish the predominant theme of nature and man being inextricably bound. The inverted image "out of hopeful green stuff woven" skilfully centers the reader's attention first on the goodness of nature rather than on the act of weaving. Characteristically, Whitman's diction is straight-forward, colloquial ("green stuff"), Anglo-Saxon as opposed to latinate--language that is consistent with Whitman's goal for his poetry to be read, appreciated and understood by common (literate) men and women.
Whitman's romantic view that God is within man is explicit in Stanza 20:
Why should I pray? Why should I venerate and be ceremonious?/Having pried through the strata, analyzed to a hair, counsel'd with doctors and calculated close/I find no sweeter fat than sticks to my own bones.
Whitman's "sweeter fat" metaphorically becomes a proxy for his soul, a conclusion he reaches after close study of conventional religion. Rather than spend his time in formal religious ceremonies--"venerate and be ceremonious"--he venerates himself because he contains within himself the same religion many people seek outside themselves. He decides that "my foothold is tenon'd and mortis'd in granite, using the imagery of carpentry to depict himself as an integral part of nature.
Using an extended metaphor of life as a journey, Stanza 46 articulates Whitman's conviction that all men (and women) must take their own journey through life, perhaps guided by a trusted friend, but the journey is an exercise in both companionship and individuality:
You must travel it yourself. . . . Shoulder your duds dear son, and I will mine, and let us hasten forth. . . . If you tire, give me both burdens . . . And in due time you shall repay the same service to me . . .
Whitman's argument throughout Leaves of Grace (and in Song of Myself) is that everyone is on an individual journey of discovery but, as human beings, we assist each other along the way as necessary, and when this journey is concluded, men and women discover that they are part of a whole, cogs in nature's wheel. Note the ellipsis in the line "shoulder your duds dear son, and I will mine"--an effective literary device because it helps carry the sense of haste with which Whitman urges the journey.
In another metaphor of haste (Stanza 51), Whitman urges the journeyer forward with him:
Who has done his day's work? who will be soonest be through with his supper?/Who wishes to walk with me?/Will you speak before I am gone? will you prove already too late?
Again, the journey is the goal here. More important, the speed of the journey is paramount. Whitman's overriding concern in these stanzas is the movement of mankind toward a goal, and the goal is not to reach the conventional ends of heaven or hell but rather to reach the state in which one becomes a leaf of grass.
Using onomatopoeia for the first time, in Stanza 52, Whitman likens himself to a hawk whose yawp brings him closer to the natural world. In an anthropomorphic frenzy, Whitman finally becomes what he has set out to be:
I bequeath myself to the dirt to grow from the grass I love,/If you want me again look for me under your boot-soles,/You will hardly know who I am or what I mean. . . .
The completed journey, in which Whitman uses nature imagery created by skillful use of a number of literary devices, moves him from man to man-in-nature, and one of his primary goals is to convince the reader that this journey is the appropriate destiny for all men and women. And Whitman's support for his fellow beings is both physical and spiritual.