The same ideals of cleanliness, order and beauty that drove the hiding of waste from the city were applied to language. A beautiful language is one that some authority has scrubbed, purging coarse words just as street sweepers removed offal, so polishing speech and sanitizing streets are one project of control.
When a law ordered each household to clean up its own doorstep and keep its own waste, filth became a private, family matter instead of a shared street problem. Taking charge of one's own waste changed how a person related to their body and to the world, helping produce the idea of the family and the inward-looking modern individual.
The modern state claims authority by setting itself up as the great cleanser of the public realm. Its power is private because it presents itself as pure and above the mess, and public because it reaches into everyone's life to purify it.
As modern life advanced, smell lost standing as a way of knowing, and appearances took over. Odors were pushed into private spaces while the public sphere was organized around what can be seen, setting the private nose against the public eye.