1 Hopeful Sociology How to Become Cosmopolitan in Urban Public Space Stéphane TONNELAT An ethnography of Philadelphia takes up a problem rarely addressed by the social sciences: how to account for events that do not take place? In his latest opus, sociologist Elijah Anderson examines the absence of discrimination in a city market and looks at the conditions of possibility of cosmopolitanism. Reviewed: Elijah Anderson, The Cosmopolitan Canopy. Race and Civility in Everyday Life, Norton Books, 2011. The social sciences have a difficult time identifying and studying positive trends affecting our urban society. And a city like Philadelphia, the setting for the book under review, seems particularly ill-suited to the task. The white middle class and businesses have long fled the inner city, encouraged by a federal policy which favored suburban development. Since the 1950s, the poor, mostly African Americans, have been left stranded in a city plagued by shrunken fiscal revenues. Today, Philadelphia is still suffering from deindustrialization and the current economic crisis is taking its toll. The social upward mobility of lower class people, again mostly African Americans, is severely impaired by poor public services (education, public transportation…) and a lack of blue-collar employment opportunities (see the Pew Report (2009) cited by Anderson). Elijah Anderson, an African American sociologist formerly at the University of Pennsylvania and now at Yale University, has built his sociological career in the steps of W. E.