* Social Inequality and Poverty: The poem paints a picture of widespread poverty, with "marks of weakness, marks of woe" evident on the faces of the poor. The "chimney-sweeper's cry" and the "black'ning church" symbolize the hardship and despair faced by those at the bottom of society.
* Oppression and Lack of Freedom: The poem highlights the lack of freedom and opportunity for the working class. The "mind-forg'd manacles" represent the social and economic constraints that bind them. The "soldier's sigh" and "harlot's curse" both suggest a sense of desperation and helplessness.
* Corruption and Exploitation: Blake criticizes the ruling class and their complicity in the suffering of the poor. The "palace walls" and "the youthful harlot's curse" imply the exploitation of the weak by the powerful.
* The Absence of Hope: The poem's bleak imagery and lack of resolution suggest a sense of hopelessness and despair. The repetition of "every" emphasizes the pervasiveness of suffering and the lack of escape.
* A Call for Change: While the poem is deeply pessimistic, it also implicitly calls for social reform. The "cry of the weak" suggests a demand for justice and equality.
In essence, "London" is a powerful indictment of the injustices and inequalities of London's society, urging readers to recognize and address the suffering of the working class. The poem serves as a reminder that social progress requires constant vigilance and a commitment to fighting against oppression and exploitation.