Final answer:
William Blake uses 'The Chimney Sweeper' to depict the loss of innocence through powerful contrasting imagery that showcases the grim realities of child labor against their natural purity.
Step-by-step explanation:
The poet William Blake, in 'The Chimney Sweeper' from his collection Songs of Innocence and Experience, illustrates the loss of innocence through the juxtaposition of the pure and grimy aspects of the chimney sweepers' lives. Blake portrays the young chimney sweep as an emblem of innocence contaminated by the harsh realities of a labor-intensive and uncaring society.
The use of contrasting imagery, such as the 'black'ning Church' alongside the innocence of the children, underscores the societal corruption leading to the loss of purity and the forced transition from childhood to the grim adult world. This loss is further exemplified by phrases like 'Every black'ning Church appalls' which highlights the disillusionment with institutions that were supposed to be pillars of moral fortitude and safety but have now become symbols of the sweepers’ suffering and the wider social injustices.