Just before I began work on my book Harmony and Dissent, I discovered a trove of photographs depicting participants in a radical German movement, Freikörperkultur (free body culture), the early years of which constituted something of a prototype for the hippie movement that would emerge in California in the 1960s. Many of the photographs were strikingly well composed, unlike more recent images of practitioners of social nudity. But these formal rigours were responsible for only a small part of their charm. More important was this: there was something unbearably sweet about these images of groups of people who were convinced that they might alleviate modernity’s depredation of charity through exposing, completely and frankly, their vulnerable naked selves to one another.