The speaker of this poem is a small boy who was sold into the chimney-sweeping business when his mother died. He recounts the story of a fellow chimney sweeper, Tom Dacre, who cried when his hair was shaved to prevent vermin and soot from infesting it. The speaker comforts Tom, who falls asleep and has a dream or vision of several chimney sweepers all locked in black coffins. An angel arrives with a special key that opens the locks on the coffins and sets the children free. The newly freed children run through a green field and wash themselves in a river, coming out clean and white in the bright sun. The angel tells Tom that if he is a good boy, he will have this paradise for his own. When Tom awakens, he and the speaker gather their tools and head out to work, somewhat comforted that their lives will one day improve.
“The Chimney Sweeper” comprises six quatrains, each following the AABB rhyme scheme, with two rhyming couplets per quatrain. The first stanza introduces the speaker, a young boy who has been forced by circumstances into the hazardous occupation of chimney sweeper. The second stanza introduces Tom Dacre, a fellow chimney sweep who acts as a foil to the speaker. Tom is upset about his lot in life, so the speaker comforts him until he falls asleep. The next three stanzas recount Tom Dacre's somewhat apocalyptic dream of the chimney sweepers’ “heaven.” However, the final stanza finds Tom waking up the following morning, with him and the speaker still trapped in their dangerous line of work.
There is a hint of criticism here in Tom Dacre's dream and in the boys' subsequent actions, however. Blake decries the use of promised future happiness as a way of subduing the oppressed. The boys carry on with their terrible, probably fatal work because of their hope in a future where their circumstances will be set right. This same promise was often used by those in power to maintain the status quo so that workers and the weak would not unite to stand against the inhuman conditions forced upon them. As becomes more clear in Blake's Songs of Experience, the poet had little patience with palliative measures that did nothing to alter the present suffering of impoverished families.
What on the surface appears to be a condescending moral to lazy boys is in fact a sharp criticism of a culture that would perpetuate the inhuman conditions of chimney sweeping on children. Tom Dacre (whose name may derive from “Tom Dark,” reflecting the sooty countenance of most chimney sweeps) is comforted by the promise of a future outside the “coffin” that is his life’s lot. Clearly, his present state is terrible and only made bearable by the two-edged hope of a happy afterlife following a quick death.
Blake here critiques not just the deplorable conditions of the children sold into chimney sweeping, but also the society, and particularly its religious aspect, that would offer these children palliatives rather than aid. That the speaker and Tom Dacre get up from the vision to head back into their dangerous drudgery suggests that these children cannot help themselves, so it is left to responsible, sensitive adults to do something for them.