Six lines, one sentence, and a sigh at the end: Shelley's fragment is a farewell to something that has barely arrived. It opens by addressing "gentle visitations of calm thought", those rare moments when the mind goes quiet and peace drifts in unbidden. The word "visitations" matters. It suggests a guest, or even a spirit, arriving from outside rather than something we produce by effort. The speaker cannot command these moods. He can only greet them and, as the last line makes clear, watch them go.
The second line gives them a curious origin: "Moods like the memories of happier earth." The phrase is not "a happier time" but a happier *earth*, as if the calm belongs to a better world, half remembered. The poem never explains this, and it is wiser not to pin it down. Judging by the phrasing, these moods feel like faint echoes of something lost or ideal, which is why they are so precious and so hard to hold.
The central image follows. The calm moods "come arrayed in thoughts of little worth, / Like stars in clouds by the weak winds enwrought." Peaceful thought, it seems, never arrives pure. It is dressed in trivial, passing ideas, just as a star glimmers through cloud. "Arrayed" suggests clothing or a procession, while "enwrought" means woven or worked, so the wind becomes a weaver patterning the cloud. The word "weak" is telling. Ordinary thinking is flimsy, shaped by feeble and random forces, yet something bright shows through it.
Then comes the turn, signalled by "But that", roughly "except that". The comparison is offered and immediately qualified. Stars are the obvious image of permanence, and the poem sets us up to expect the moods to behave like them. Instead the last two lines mirror each other: "the clouds depart and stars remain, / While they remain, and ye, alas, depart!" The verbs form a cross, depart, remain, remain, depart, so that the sentence closes around its own meaning. The stars stay and the calm leaves. The simile has been built only so it can fail, and that failure is the real subject of the poem.
The sound of the lines supports this. The rhythm is mostly steady iambic pentameter, a measured, quiet pace that suits the subject. Line 2 runs slightly full if every syllable of "memories" and "happier" is sounded, but the voice can glide over them, like a thought that slips by. The rhyme scheme starts out tightly enclosed: "thought" and "enwrought" frame the pair "earth" and "worth". That gives the opening a settled, contained feeling, like a mind at rest. But "remain" and "depart" do not rhyme, and the final word has no partner. Whether this is deliberate or simply because the piece is a fragment, I cannot say, but the effect is hard to ignore. The poem ends on "depart" with nothing to answer it, as the moods themselves leave without return. "Alas" is the only openly emotional word in the poem. Everything before it is controlled description, so the exclamation lands with extra force.
What makes this small piece worth reading? First, its honesty about inner life. It does not claim that peace is a permanent reward for thinking deeply. It says our best moments are tangled up with our most trivial ones and disappear first. Second, it shows how a poem can argue with its own comparison. Most similes simply decorate, but here the image of stars in clouds is tested, found partly true and partly false, and the gap between the two is where the feeling lives. Third, it fits a great deal into very little space: an address, a memory of a better world, a picture of sky and weather, a reversal and a cry. Even incomplete, it feels finished in the way a held breath does when it is let go.