What argument is Carl Sandburg making in this quote about poetry?

"Poetry is the journal of the sea animal living on land, wanting to fly in the air. Poetry is a search for syllables to shoot at the barriers of the unknown and the unknowable. Poetry is a phantom script telling how rainbows are made and why they go away."

This quote describes Sandburg's belief that poetry is meant to go beyond the everyday and prosaic to explore what seems impossible and to express what seems unknowable or what goes beyond the scientific.

In the first line, Sandburg compares poetry, first, to a sea animal living on land. In other words, poetry takes a living being out of its known and comfortable environment and places it in a new world. Beyond that, poetry takes living creatures who have already transcended their normal environment and encourages them to aspire for even more, not only to breathe air but to soar to the sky. This line is, in a nutshell, saying that poems show us limitless possibilities.

In the second line, Sandburg likens poetry to a language that strikes down barriers and decodes the "unknowable." It delineates what we know and don't know, then steps beyond the conventional boundaries of knowledge to strive for deeper understanding. It tries, in other words, to open up us through words to new possibilities about life. Poetry uses its words to keep us from limiting ourselves.

In the third line, Sandburg calls poetry a "phantom script" that tells how "rainbows are made and why they go away." A phantom script is ghostly, a message from the spiritual realm. The implication is that poetry explains phenomena like rainbows, themselves mysterious parts of nature, not in terms of science, but in light of their spiritual or higher meaning, of how they effect us emotionally or perhaps bring us closer to another, more unseen world of the imagination. A poet would have a much different explanation than a scientist for why rainbows appear and disappear.

How can Carl Sandburg's quote be used in a speech reflecting on three poems and their poetic elements?

"Poetry is the journal of the sea animal living on land, wanting to fly in the air. Poetry is a search for syllables to shoot at the barriers of the unknown and the unknowable. Poetry is a phantom script telling how rainbows are made and why they go away."

This quote speaks to the power of poetry to break beyond the rational. Poetry allows us to express feelings our souls experience that can't be scientifically quantified. The quote praises the possibility of poetry to break imaginative boundaries in ways that help us see the joys (or sorrows) of the world in a heightened way.

If you use something like the opening above—you would want to make that your own—as your opening thesis, you could incorporate the quote into your first paragraph and then refer to it again as you discuss the three poems that illustrate your theme. The three poems used as examples here show the way poems allow the imagination's expression, but you could certainly choose your own.

First, consider Emily Dickinson's "I taste a liquor never brewed –" which uses a series of vibrant metaphors to compare her experience of nature's beauty to the heady feeling of intoxication that can come from a love of nature, if you really experience it fully. It encourages us to move beyond the mundane. It is the "journal of sea animal living on land, wanting to fly."

The second poem, one that shoots "at the barriers of the unknown and unknowable," is John Donne's "A Valediction Forbidding Mourning," in which he uses highly unusual metaphors to show that although he and his beloved will be separated, their souls will always be connected. As he moves farther away from her, their connection merely stretches out. The poem puts words around the sense of being close to a loved one no matter how far you are apart geographically. Their connection is still there, but:

Like gold to airy thinness beat.

The third poem used here is "Metaphors" by Sylvia Plath, which describes the feelings of being pregnant. It doesn't tell us how rainbows are made, but it is similar as it is a fanciful way of discussing how babies are made and the changes that bring to a woman:

I’m a riddle in nine syllables [months],
An elephant, a ponderous house,
A melon strolling on two tendrils.
...
This loaf’s big with its yeasty rising.

As for structure, you could state your opening thesis, go through the poems one by one, attaching each to one of the three parts of the quote. Then, end with the way these poems add intensity, wonder, and meaning to common experiences, such as being out in nature, a separation from a loved one, and pregnancy.

Other poems that may work well with this quote are the very emotionally moving "O Captain! my Captain!" by Walt Whitman, which mourns Lincoln's assassination by imaginatively seeing him as a captain who dies as he safely brings his ship to port, and Ginsberg's exuberant "Supermarket in California," which, if ironically, heightens our experience of shopping.

You could organize your talk by explaining the meaning of the Sandburg quote in your opening, then move to applying it to the three poems you have chosen. All three of the poems deal with either death or aging, which aligns with Sandburg's assertion that poetry encourages us to think beyond the mundane or everyday aspects of life to imagine what seems difficult to grasp.

Shakespeare's "Sonnet 71" or "No longer mourn me when I am dead" expresses the speaker's deep love for his beloved by asking her to forget him when he is dead. This is because, as he puts it:

For I love you so,
That I in your sweet thoughts would be forgot,
If thinking on me then should make you woe.

Better by far you should forget and smile
Than that you should remember and be sad.