Before the poem says a word about love, it has already smashed a lamp. The opening stanza is a run of broken things: a shattered lamp, a scattered cloud, a broken lute, spoken words that fade. Each one ends the same way. The light "lies dead" in the dust, the rainbow's glory is "shed," the sweet tones are "remembered not." Beauty here is never free-standing. Light needs a lamp, a rainbow needs a cloud, music needs a lute. Once the physical thing goes, so does everything it carried.
The second stanza turns that observation on the human heart. Music and splendour do not outlast the lamp and the lute, and in the same way "the heart's echoes render / No song when the spirit is mute." What remains is "sad dirges, / Like the wind through a ruined cell," or the "mournful surges" that ring "the dead seaman's knell." The images shift from small, domestic objects to bleak, open landscapes: an empty stone room, the sea tolling for a drowned man. The grief grows as we read.
Then the poem speaks directly to Love itself. The third stanza is blunt about who suffers: "Love first leaves the well-built nest; / The weak one is singled / To endure what it once possessed." Love does not die alongside the relationship. It departs first and leaves one person behind to live among what they once had. Then comes the poem's central question, addressed to Love in the tone of a reproach: "Why choose you the frailest / For your cradle, your home, and your bier?" The last line packs birth, life and death into three nouns. Love is born in the human heart, lives there, and is buried there, and the heart is the least durable place it could have picked.
The final stanza follows this logic through, using the nest as a metaphor. Love's home is first battered by passion, which will "rock thee / As the storms rock the ravens on high." Then it is mocked by "bright reason," which shines "like the sun from a wintry sky": light without warmth, clear and no comfort. Finally the structure itself fails: "every rafter / Will rot," and Love is left "naked to laughter." The nest started as a bird's home, but words like "rafter" make it a house too, and rotting timber is a more human kind of ruin than a storm. The poem's last image is not death but exposure and mockery, which may be worse.
The sound of the poem works against its message. The lines are short, with a lilting, almost singing movement, and the rhymes alternate between two-syllable pairs ("shattered/scattered," "broken/spoken," "dirges/surges") and one-syllable ones ("dead/shed," "not/forgot"). Each stanza therefore ends on a firm, closing beat, like a door shutting. It is a poem about songs that cannot survive, and it is itself very musical. That tension is part of its pathos. The song exists only as long as the poem is being read, which is exactly the fragility it describes.
Look also at how the poem is built. The first stanza leans on "When" clauses, setting out a pattern like a law of nature. The second stanza answers with "As… " and brings in the heart. The third and fourth shift to "O Love!" and "thee," so that an abstract idea becomes a vulnerable creature with a nest, and the argument becomes a plea and then a prophecy. The title, "Lines," is little more than a label, so the first line serves as the poem's name, and that opening image of the broken lamp is what stays in the mind.
The poem matters because it denies love the comfort of permanence without sneering at love. Its complaint is that something so valuable has been lodged in something so breakable, and the final stanza gives no consolation. For a young reader, the surprise is how plain the writing is. There are no obscure references, only light, music, wind, sea and a ruined nest. Out of those simple materials the poem builds a sorrow that is hard to argue with.