“Frost at Midnight” is a poem about reflection. Just as Coleridge’s frosted windowpane would reflect the lighted cottage’s interior more vividly than it would display the dark exterior, his observations about the outside world ultimately reflect his inner life and concerns. His thought focuses on the different ways things reflect one another, from the owlet’s echoed cry to how children grow up to reflect their environments. The most prominent mode of reflection in “Frost at Midnight,” however, relates to the act of mental reflection and its role in understanding the world.

Coleridge’s long reflection begins with the world outside his cottage. He notes the “[f]rost” (Line 1) and an “owlet’s cry” (Line 2), which comes “loud—and hark, again!” (Line 3). The immediate repetition of the owlet’s cry in Coleridge’s silent outdoor scene suggests that the second call is actually an echo. His insistence that the second cry is “loud as before” (Line 3) reinforces this idea. Since he does not distinguish between the cries as separate events, the phrase “again! Loud as before” (Line 3) implies a repetition of the same cry reflected. The echo’s ability to maintain its volume underlines the stagnant air and “extreme silentness” (Line 10) Coleridge experiences.