According to critic Norman Lacey, Wordsworth built his reputation as a "poet of nature". Early works, such as "Tintern Abbey", can be viewed as odes to his experience of nature. His poems can also be seen as lyrical meditations on the fundamental character of the natural world. Wordsworth said that, as a youth, nature stirred "an appetite, a feeling and a love", but by the time he wrote Lyrical Ballads, it evoked "the still sad music of humanity".
The five "Lucy poems" are often interpreted as representing Wordsworth's opposing views of nature as well as meditations on the cycle of life. They describe a variety of relationships between humanity and nature. For example, Lucy can be seen as a connection between humanity and nature, as a "boundary being, nature sprite and human, yet not quite either. She reminds us of the traditional mythical person who lives, ontologically, an intermediate life, or mediates various realms of existence." Although the poems evoke a sense of loss, they also hint at the completeness of Lucy's life—she was raised by nature and survives in the memories of others. She became, in the opinion of the American poet and writer David Ferry (b. 1924), "not so much a human being as a sort of compendium of nature", while "her death was right, after all, for by dying she was one with the natural processes that made her die, and fantastically ennobled thereby".
Cleanth Brooks writes that "Strange fits" presents "Kind Nature's gentlest boon", "Three years" its duality, and "A slumber" the clutter of natural object. Other scholars see "She dwelt", along with "I travelled", as representing nature's "rustication and disappearance". Mahoney views "Three years" as describing a masculine, benevolent nature similar to a creator deity. Although nature shapes Lucy over time and she is seen as part of nature herself, the poem shifts abruptly when she dies. Lucy appears to be eternal, like nature itself. Regardless, she becomes part of the surrounding landscape in life, and her death only verifies this connection.
The series presents nature as a force by turns benevolent and malign. It is shown at times to be oblivious to and uninterested in the safety of humanity. Hall argues, "In all of these poems, nature would seem to betray the heart that loves her". The imagery used to evoke these notions serves to separate Lucy from everyday reality. The literary theorist Frances Ferguson (b. 1947) notes that the "flower similes and metaphors become impediments rather than aids to any imaginative visualization of a woman; the flowers do not simply locate themselves in Lucy's cheeks, they expand to absorb the whole of her ... The act of describing seems to have lost touch with its goal—description of Lucy."
The poems Wordsworth wrote while in Goslar focus on the dead and dying. The "Lucy poems" follow this trend, and often fail to delineate the difference between life and death. Each creates an ambiguity between the sublime and nothingness, as they attempt to reconcile the question of how to convey the death of a girl intimately connected to nature. They describe a rite of passage from innocent childhood to corrupted maturity and, according to Hartman, "center on a death or a radical change of consciousness which is expressed in semi-mythical form; and they are, in fact, Wordsworth's nearest approach to a personal myth." The narrator is affected greatly by Lucy's death and cries out in "She dwelt" of "the difference to me!". Yet in "A slumber" he is spared from trauma by sleep.
The reader's experience of Lucy is filtered through the narrator's perception. Her death suggests that nature can bring pain to all, even to those who loved her. According to the British classical and literary scholar H. W. Garrod (1878–1960), "The truth is, as I believe, that between Lucy's perfection in Nature and her death there is, for Wordsworth, really no tragic antithesis at all." Hartman expands on this view to extend the view of death and nature to art in general: "Lucy, living, is clearly a guardian spirit, not of one place but of all English places ... while Lucy, dead, has all nature for her monument. The series is a deeply humanized version of the death of Pan, a lament on the decay of English natural feeling. Wordsworth fears that the very spirit presiding over his poetry is ephemeral, and I think he refuses to distinguish between its death in him and its historical decline."