Solidarity--the reciprocal relations of trust and obligation between citizens that are essential for a thriving polity--is a basic goal of all political communities. Yet it is extremely difficult to achieve, especially in multiracial societies. In an era of increasing global migration and democratization, that issue is more pressing than perhaps ever before. In the past few decades, racial diversity and the problems of justice that often accompany it have risen dramatically throughout the world. It features prominently nearly everywhere: from the United States, where it has been a perennial...

In 1845 two thinkers from the American hemisphere - the Argentinean statesman Domingo Faustino Sarmiento, and the fugitive ex-slave, abolitionist leader, and orator from the United States, Frederick Douglass - both published their first works. Each would become the most famous and enduring texts in what were both prolific careers, and they ensured Sarmiento and Douglass' position as leading figures in the canon of Latin American and U.S. African-American political thought, respectively. But despite the fact that both deal directly with key political and philosophical questions in the...