In the first stanza, the speaker introduces an unidentified “force” that raises the stems—or "fuses"—of flowers, as well as powering the speaker’s youth and liveliness. Yet despite these positive images, the force also destroys trees, and even the speaker himself. The speaker is in such awe of the force that he is momentarily unable to speak. The powerful, industrial language the speaker uses, such as "fuse," "drives," and "blasts," conjures an image of rapid growth and just-as-sudden destruction.
In the second stanza, the force causes water to course through a stream, and blood to flow through the speaker’s veins, but it also dries both liquids. Just as drying the speaker's blood would cut off his life prematurely, drying the stream's "mouthing" water eradicates it before it can reach the pool the mouth pours into. Additionally, it is this force that, through his own mouth, draws nourishment from a mountain spring—though the speaker reflects that, paradoxically, he cannot use that mouth to describe the force, an example of irony.
The third verse conjures an image of a hand swirling quicksand and controlling the wind, while both powering a ship forward and hastening towards death (“shroud sail.”) In the stanza's final line, the speaker refers to “lime”—the substance bodies were buried in to decay—and mentions the paradox that this very substance can be derived from the human body ("clay"--an allusion to a common, cross-cultural myth of the creation of mankind from clay). Thus, the speaker considers himself part of this process of decay.
In the fourth verse, the force—now named explicitly as time—sucks from the fountain head, like the mountain spring earlier. The speaker personifies love as a grotesque creature whose "sores" are healed by blood, though the source of the blood isn't clear. He again finds himself incapable of communication, too overwhelmed to speak to the wind, which could carry his message. In the final couplet, the speaker is again unable to communicate, stunned by a metaphorical “worm” gnawing at his burial shroud.
The language of the first stanza is dynamic and potent, underscoring the sheer power of the as-yet-unnamed "force" that is the poem's great subject. This language—powerful verbs like "force" and "drives," as well as "blasts" and "bent"—establishes the force as both positive and essential to life, and negative and deadly. The first stanza also introduces the parallels between the speaker and nature that will become central to the poem.
Stanza two continues these parallels by linking together the flow of water in a river and blood in the speaker’s body. Water often symbolizes life in poetry, making this connection especially significant. These first two stanzas follow similar patterns, both beginning with the words "the force" and moving to directly reference the speaker's body, a pattern that is disrupted in the following stanzas.
In the third stanza, the speaker describes a hand that is stirring deadly quicksand, and is capable of causing a boat either to sail successfully or to crash on the rocks, reinforcing its power over life and death. This "hand" also resonates metaphorically as the "hand" on a clock, suggesting that it is time itself that is stirring the quicksand or guiding a boat. The same hand "ropes my shroud sail”—referring both to the "shrouds" that hold up the mast of a ship, and to the "shroud" or cloth which is used to cover a dead body. The phrase "shroud sail" may be an allusion to Greek mythology, in which a ship ferried by the character Charon serves as the boundary between life and death.
The speaker also forms a connection between himself and a dying man, seeing himself in the man’s death—his “clay,” or body, composes the lime the man is buried in. The idea that humans were originally formed by a deity out of clay or soil is a common one in mythology, appearing in both the Greek myth of Prometheus and Genesis 2:7 ("And the Lord God formed man of the dust of the ground"), as well as in Maori, Egyptian, and Incan mythology, and more.
In stanza four, the speaker envisions time sucking at the fallen blood of love, devouring the vitality of love to sustain itself. Finally, the speaker imagines a similar image—the worm eating the burial shroud to stay alive.
These later stanzas depart from the pattern established in the first two: none reference the growth and destruction of speaker's body explicitly in the manner the first and second name his "green age," "youth," and "red blood," and they no longer begin with the phrase "the force." Furthermore, the third line of each stanza throughout the poem is only about half as long as the others, another variation on established convention. These deviations from the pattern are unexpected and unsettling. They underscore the speaker's point that he is "dumb," or unable to express himself—the form of expression he chooses isn't sufficient, so he must struggle to escape it, breaking with recognizable form.
William T. Moynihan, the author of a book on Thomas’s poetry, writes that throughout the poem “the destructive and creative forces of life are viewed from five different perspectives…yet all derive from the feeling, or perception, of decay in the very process of growth.” In this manner, decay emerges as the central idea of the poem. “All the images in the poem may be said to spring from this seed,” he contends. The poem itself can be said to "decay," as the established form slips further away until the final couplet, a radical departure from the previous quintains.
In an essay about the poem, critic Philip A. Lahey argues that “the final half-rhymed couplet resigns itself to the problems…of manipulating the conventional images and terms of traditional poetry in order to express the union [the speaker] feels between himself and the universal forces of nature.” “This confession, itself part of the convention, reveals the essential isolation of a poet who feels unable to manipulate his material within the conventional pattern of his verses,” he writes, adding that the speaker’s ability to communicate fails when he attempts to express how he is involved in the cycle of life and death. Thus, the poem also carries a meaning related to the creative process and the difficulty of adequately communicating one’s thoughts and feelings. The departures from the convention of the poem further this theme, as the format that the speaker chooses to express his thoughts does not allow him to do so effectively, forcing him to struggle with it.