The speaker integrates the usage of metaphor into his poem in order to reflect the relationship between humans and nature, and their relation to the theme of life and death. The first stanza of the poem, states that “the force that through the green fuse drives the flower drives my green age.” This central metaphor drives the meaning of the poem as a whole. From this line, it can be noted that the “force” that “drives” nature is the force of vitality that drives the poet throughout the poem. The central metaphor is based on the use of the word “force,” and is the same force that establishes a relationship between the force of nature and the force of life that flows within humans. There is a strong implication of dawning death in the images of the poem.The speaker is aware that he will die naturally over time comparatively to the flowers and trees in nature. In this way, nature acts as a destroyer as well as a creator. The metaphorical force, which continues throughout the poem, is intended to generate a sense of the close relationship between nature and humankind. This is further emphasized when the poet says that the force “drives my green age,” because the color green is used to represent life, and by contradicting “green” with the aspect of “age,” it can be inferred that a correspondence exists between the characteristics of nature and human life. Several other metaphors can be found in this poem, particularly references of time. Time has been compared to the abstract “force that drives my green age.” This metaphor is so vibrant that both the creative, and destructive qualities of time are vividly depicted in one mention, which also implies the unity of creation and destruction. The lines “my youth is bent by the same wintry fever” and “how at the mountain spring the same mouth sucks” are another two metaphorical pronouncements of time that contain two terms that are normally considered as opposites. “Wintry fever” creates a serious and supernatural quality on time while the “same mouth sucks” gives it a vampiric like quality as the force sucks life away. Another metaphor can be seen in the line “hauls my shroud sail.” The boat has a “shroud sail,” and a shroud is the cloth used to wrap a dead body, so this line showcases the unavoidable trek towards death that all life leads to. The usage of metaphor within the poem showcases the relationship between humans and nature, and their relation to the theme of life and death.