The quote from Victor Hugo's "Les Misérables" suggests that the evolution of society can be closely linked to the development of its infrastructure, particularly in the context of sewers. This analogy implies that the hidden aspects of civilization, like sanitation systems, reflect the overall moral and social condition of humanity. As societies advance, their handling of waste and public health improves, revealing how civilization prioritizes the well-being of its people.

Moreover, Hugo's statement points to the interconnectedness of social progress and the struggles faced by individuals in society. By examining the darker and often overlooked parts of urban life, the quote emphasizes that understanding history requires an appreciation of even the unglamorous foundations that support it. In essence, a society's treatment of its sewers symbolizes its values, priorities, and the overall state of human dignity.