A wagging tail is hardly the stuff of grand poetry, and that is exactly where Emily Dickinson starts. In four short stanzas she makes a quiet argument about happiness: the purest kind needs no reason, and some people cannot bear to see it. The poem looks like a sketch of household animals and a child, but it ends as a gentle satire on the people who hush them.
The comparison in the first stanza runs in an unexpected direction. We usually say a puppy is like a child, but here the speaker sees a boy and is "Reminded" of a dog, one who "knows no other joy." That phrase is both comic and a little enviable, since the dog's whole inner life is one cheerful gesture. The boy "gambols," a verb we normally keep for lambs and young animals, so he has already slipped across the line into the animal kingdom. His happiness comes "Without an earthly cause," and the word "earthly" carries a faint suggestion that this joy belongs to some higher order of things. Then comes the speaker's deadpan "I honestly suppose," which sounds like a scientist cautiously recording an observation. The mock-seriousness makes the idea more charming. Boys are joyful "Because" they are boys, and that is the only explanation on offer.
The cat in the third stanza changes the mood. Her day is "martial," as if hunting were a military campaign, and the mouse has become "but a Tradition now," something half-remembered from history. She seems like a retired soldier, living out a "desireless Lot." Judging by the language, she is not unhappy so much as stilled. She stands between the wagging dog and the final stanza, where energy has been drained out rather than simply absent. Dickinson never explains why the cat has lost her appetite for the chase, and the poem is better for leaving that open.
Then the poem turns on "Another class." The word is taxonomic, as though these people were a separate species. They "neither please nor play," and they spend their effort begging each boy not to "make a 'bit of noise.'" The quotation marks let us hear the phrase as a stock nagging line, the sort of thing said again and again. "Beseech" is an absurdly grand word for such a small request, and the mismatch is funny. The poem never says who this class is, but the contrast with the playful boy suggests solemn grown-ups, or perhaps anyone who has made quietness a virtue.
The form supports the joke. Lines alternate between four beats and three, roughly the pattern of a hymn or ballad stanza, so a dog and a boy are treated with the dignity of a church song. The rhymes are loose and sometimes only half-true. "Joy" and "Boy" chime at the start, "forgot" and "Lot" close the cat's stanza, and "cause" and "suppose" only nearly match. In the last stanza "noise" and "Boy" share their vowel sound, an echo of the earlier "joy." It is as if the poem's sound itself carries joy over into noise, the very thing the scolds want to stop. Dickinson's capitals for Dog, Boy, Cat and Mouse make them feel like characters in a miniature fable, and the poem finishes on a dash, so the plea hangs unanswered. We never hear whether the boy obeys.
What makes the poem worth reading is its lightness. Dickinson, who wrote almost eighteen hundred poems, often packs large ideas into small spaces, and here she does it with a joke. She does not lecture anyone about spontaneity. She lets a dog, a boy and a bored cat make the case, then lets the humourless "class" give themselves away through their own begging. The poem's quiet suggestion is that joy needs no justification, and that it is the people demanding silence who have something to explain.