The final couplet signifies Lucy’s death as both woman and muse. As woman, her deceased body naturally returns to the earth. Because the poet's source of inspiration is the natural world, which is made clear throughout the Lucy series, it figures that Lucy returns to the “rocks, and stones, and trees.” This emphasis on the natural world is a theme that arises in a great deal of Romantic poetry.

The figure of Lucy dies on two levels: as physical woman and as ethereal muse. Some of the vivacious qualities a person loses in death—movement and sense perception—double as elements of poetic practice. A poet without a muse cannot write with force, nor offer aural and visual details. The combined loss of both muse and lover is one of the central themes of the Lucy poems.

The speaker reinforces Lucy’s ethereal, immortal nature as muse. In the ancient Greek tradition, muses are not understood to be personal to each poet. Rather, they are goddesses who visit poets and bards as they choose. Wordsworth depicts such a relationship between Lucy and the speaker, who yearns for the presence of his muse but finds himself at a loss. The speaker’s idealistic desire to find forces beyond the empirical world is exemplary of the themes and beliefs of the Romantic movement.

Though Lucy is not named in the poem, the speaker’s “spirit” serves as a reference to her: “my spirit” is the antecedent to all subsequent instances of “she.” Wordsworth’s word choice here is important. In the Oxford English Dictionary, “spirit” is defined as “that which gives life to the physical organism, in contrast to its purely material elements.” This is an apt characterization of Lucy, who represents the speaker’s poetic muse and imagination. In the speaker’s sleep state, the muse is “sealed,” and thus present to the poet.