Possibly being the most important aspect of this poem, Blake has many instances where the text is laced with irony. The first example is the use of the word "duty." Chimney sweepers range anywhere from ages four to seven; the only duties a child of this age should have is to go to school and play with friends, not work as child laborers. Ironically, the sweeps' masters told them it was their duty to clean the chimneys, and if they did not they would not go to Heaven. Tom's dream also was ironical as everything was joyous and they were free to leap and frolic yet he still woke up to the world of oppression. He went to work feeling "happy and warm" when it was a job that essentially would kill him. This statement, "So if all do their duty, they need not fear harm," further contradicts reality as by doing their duties, they in fact did cause harm to their bodies. Most chimney sweeps died at age fifteen due to lung disease, cancer, or tuberculosis and their bodies became deformed from the average nine inch in diameter chimneys they ascended. Many viewed them as subhuman due to their unwashed bodies, and twisted kneecaps (An Analysis). It is apparent that there is great polarity between what the child says in the poem, and what Blake is actually implying.
