It is the big city that protects what is unusual, writes a sociologist at the turn of the century, and that makes it more unusual still: The city is the spectroscope of society; it analyses and sifts the population, separating and classifying the diverse elements. The entire progress of civilization is a process of differentiation, and the city is the greatest differentiator. The mediocrity of the country is transformed by the city into the highest talent or the lowest criminal. Genius is often born in the country, but it is brought to light and developed by the city [just as] the boy thief of the village becomes the daring bank robber of the metropolis.

• From Frano Moretti’s Distant Reading