However, while the poem conforms to many of the guiding principles of Romanticism, it also highlights a key difference between Coleridge and his fellow Romantics, specifically Wordsworth. Wordsworth, raised in the rustic countryside, saw his own childhood as a time when his connection with the natural world was at its greatest; he revisited his memories of childhood in order to soothe his feelings and provoke his imagination. Coleridge, on the other hand, was raised in London, “pent ’mid cloisters dim,” and questions Wordsworth’s easy identification of childhood with a kind of automatic, original happiness; instead, in this poem he says that, as a child, he “saw naught lovely but the stars and sky” and seems to feel the lingering effects of that alienation. In this poem, we see how the pain of this alienation has strengthened Coleridge’s wish that his child enjoy an idyllic Wordsworthian upbringing “by lakes and sandy shores, beneath the crags / Of ancient mountain, and beneath the clouds...” Rather than seeing the link between childhood and nature as an inevitable, Coleridge seems to perceive it as a fragile, precious, and extraordinary connection, one of which he himself was deprived.

In expressing its central themes, “Frost at Midnight” relies on a highly personal idiom whereby the reader follows the natural progression of the speaker’s mind as he sits up late one winter night thinking. His idle observation gives the reader a quick impression of the scene, from the “silent ministry” of the frost to the cry of the owl and the sleeping child. Coleridge uses language that indicates the immediacy of the scene to draw in the reader; for instance, the speaker cries “Hark!” upon hearing the owl, as though he were surprised by its call. The objects surrounding the speaker become metaphors for the work of the mind and the imagination, so that the fluttering film on the fire grate plunges him into the recollection of his childhood. His memory of feeling trapped in the schoolhouse naturally brings him back into his immediate surroundings with a surge of love and sympathy for his son. His final meditation on his son’s future becomes mingled with his Romantic interpretation of nature and its role in the child’s imagination, and his consideration of the objects of nature brings him back to the frost and the icicles, which, forming and shining in silence, mirror the silent way in which the world works upon the mind; this revisitation of winter’s frosty forms brings the poem full circle.