Four short lines, and Emily Dickinson fits an entire theory of how feeling behaves in time into them. Happiness, she says, leaves without a trace. Anguish, by contrast, stays exactly where it is. The poem never describes a particular joy or a particular grief. It states a rule, and the rule is uncomfortably easy to recognise: the good afternoon is gone before we've understood it, while the bad night will not end.
The first two lines work by quiet subtraction. "Too happy Time dissolves itself" gives us no thief and no disaster. Happy time does the destroying on its own, as sugar vanishes into water. The reflexive "itself" suggests that the happiness is what undoes it. The word "Too" carries the same suspicion. It may describe a time that is too happy, or happiness too intense to last, and the poem lets both readings stand. Then comes "remnant," a word that belongs to cloth and shops, meaning the scrap left over when the rest has been used. Joy leaves not even that. "No remnant by" means nothing set aside and nothing kept close at hand.
The second half turns on a sentence that is slightly twisted: "'Tis Anguish not a Feather hath / Or too much weight to fly." The inverted word order and the old-fashioned "hath" give it the ring of a proverb or a line from scripture. The small word "Or" is the most interesting thing here. Anguish either has no feather at all, and so no wings, or it has too much weight to use them. The speaker offers two explanations and does not choose between them. She is certain of the result and unsure of the cause. Either way, anguish cannot lift off and leave. The feather is a well-chosen image, since it is the lightest part of a bird and so the very opposite of the heaviness she describes. We usually say that time flies. Here happy time melts away, and the only thing in the poem that would need to fly is the one thing that can't.
The form is plain. The lines alternate between eight and six syllables in a mostly iambic beat ("Too HAP-py TIME dis-SOLVES it-SELF"), the pattern of the hymn. Dickinson often used this familiar, singable measure, and here it sets up a small irony, because the comforting tune delivers news that offers no comfort. Only the second and fourth lines rhyme, "by" with "fly." That single rhyme works like a latch clicking shut, and it puts the poem's last word on the very action it denies. The open vowel of "fly" sounds light, even as the sentence insists on weight.
Sound reinforces sense in smaller ways. The first line is full of soft, hissing consonants ("happy Time dissolves itself"), which seem to fade as you say them. The third line is heavier, with the clogged "ng" of "Anguish" and the flat thud of "not" and "hath." The dashes matter too. The first one hangs at the end of line two, pausing before the turn to anguish. The last one comes after "fly," and the poem trails off into silence, as if no further words could change anything. The capital letters on Time, Anguish and Feather make each one stand like a character in a miniature fable.
What makes the poem worth reading is that it refuses to console. Many poems promise that sorrow passes or that joy can be held. Dickinson, who lived in Amherst, Massachusetts, and left most of her poems unpublished in her lifetime, offers neither. She records an imbalance that most readers already know from experience and then stops, trusting twenty-odd words to do the work. The poem is small enough to memorise in a minute and hard to shake off for much longer. Like the anguish it describes, it stays put.