William Blake's poem "London" shows how this city, the supposed center of culture, actually embodies the wasted potential of humanity. In the first stanza, the speaker notes that the streets and even the river is "charter'd," meaning it is owned. The fact that the freely flowing river is owned is a statement about the governing bodies and businesses of London owning life itself, since water is a necessity of life.
In the second and third stanzas, the speaker listens to the anguished cries under political and legal oppressions ("bans") which leads the reader to interpret that these limitations suppress the human spirit; not just social practices. This limitation of the human spirit and human life is "marked" by the word "weakness."
And mark in every face I meet
Marks of weakness, marks of woe.
The faces are "marked" with this limitation. That is, their facial expressions communicate this repression, but it is also as if they are stamped (marked) or conditioned to feel this way.
The third stanza ends with the tragedy of the soldier who dies to protect this gloomy way of life.
In the last stanza, the speaker notes the prostitutes cursing and this could be a comment on the buying and selling of (at least physical) love. The speaker also condemns marriage itself, comparing it to a legal limitation, perhaps an even greater imprisonment for the wife than the husband. Interestingly, "bans" used before to indicate political and legal prohibitions, can also be spelled "banns" and this means a marriage proclamation. The speaker sees legal, political and even marital bonds as limitations or chains on the human spirit.
Coming from Blake's Songs of Innocence and Experience, "London" is a "Song of Experience." The urban landscape (the river being the only natural reference) is "charter'd," implying that social code is based on buying and sellling. The songs of experience are contrasted with the songs of innocence, which have more natural, happy, optimistic images. "London" is an indictment of English society, the monarchy, the church, and the law. In this poem, Blake addresses the ways in which these institutions affect and repress daily life in London.