Every society has rebels, outlaws, troublemakers, and deviants. This collection of primary sources takes readers on a journey through the intellectual and cultural history of the "underground" in the nineteenth and twentieth centuries. It demonstrates how thinkers in the US and Europe have engaged in an ongoing trans-Atlantic dialogue, inspiring one another to challenge the norms of Western society. Through ideas, artistic expression, and cultural practices, these thinkers radically defied the societies of which they were part. The readings chart the historical evolution of challenges to mainstream values -- some of which have themselves become mainstream -- from the beginning of the nineteenth century to the present.