In "Les Misérables," Victor Hugo explores the contrast between the pretense of societal norms and the authentic reality of human experience. He suggests that the complexities and facades upheld by society—such as politics and moral righteousness—often obscure the genuine nature of existence. The overwhelming display of virtue can at times feel insincere, particularly in the face of life's harsher truths.

The quote reflects a deep appreciation for the raw and unembellished aspects of life, likening the truth found in the muck of a sewer to a comforting relief from the oppressive weight of societal expectations. It implies that accepting and recognizing this reality can bring solace to the soul, allowing individuals to confront the authentic human condition beyond the grand illusions that society presents.