Surén's thinking about Nacktkultur was not entirely original, for he relied on some arguments made before World War I. What was original (and popular) about his presentation was the ingenious way in which he made Nacktkultur attractive by implying that the problem of erotic desire was not a matter for Nacktkultur to solve—that problem was the responsibility of those who did not know their bodies. But Surén by no means spoke for everyone involved with Nacktkultur . Adolf Koch, for example, never placed such heavy emphasis on the connection with nature. A former schoolteacher, he saw nudity as a pedagogical activity that integrated the study of the body and the study of culture to create a kind of athletic intellectual. But because he favored the integration of the sexes in nudism, which he regarded as a necessary component of sexual hygiene, it was even less clear to what extent his approach met or neutralized the expectations raised by erotic desires. That he accepted this erotic ambiguity was evident from the beginning (Figure 9). In 1921, as a public school teacher in a proletarian section of Berlin, Koch introduced open-air nude exercises to male and female children suffering from the effects of vitamin deficiency. The state was sympathetic to his program until a woman visitor to the school made a loud public complaint against "nude dancing" in a state institution. School authorities
forbade him from doing anymore nude exercises, so he decided to form his own school in 1926 (Koch, Nacktkulturparadies , 37; Merrill 146).
Koch was unique in that he did not merely form a nudist organization; he founded a nudist school . Naked students attended classes on all sorts of subjects and participated in gymnastics, group movement exercises, nude theatricals, and outdoor activities. Unlike Surén, Koch was enthusiastic about drills and group coordination exercises (Merrill 134–148). He also aggressively recruited proletarian men and women into nudism. His success was considerable, partly because all members paid the Koch organization 5 percent of their income; if they were unemployed, as many were after 1930, the school carried them until they found a job. Meanwhile, Koch found friends among mainstream socialists, although he acknowledged that Nacktkultur alone could not dissolve class differences and was not sure that nudism was a reliable model for a new, socialist society (Koch, Nacktheit , 126). Nevertheless, by 1930 he had schools in Berlin, Breslau, Barmen-Elberfeld, Hamburg, Ludwigshafen, and Mannheim, with a total enrollment of 60,000; the same year, Koch revealed that the total enrollment in all German nudist organizations was more than 3 million. The Koch schools offered four-year teaching certificates accredited by the government.
In 1929 the Berlin school hosted the first International Congress on Nudity, with participants from twenty-three countries. In Berlin, Koch also presided over a busy publishing program and edited the nudist journal Körperbildung/Nacktkultur (1928–1932), which, unlike the majority of the ever-expanding number of nudist magazines reaching the public, stressed the idea of nudism as an indoor, classroom activity. An American documentary film, This Nude World (1932), containing English commentary by Koch's daughter, presented a mysterious image of a community, not entirely young, in which nudism not only created a powerful feeling of social unity but was the basis for an even more profound unity between intellectual development and appreciation of nature. Koch was clearly a rationalist, but he had little interest in Dalcrozian rhythmic gymnastics, for his sense of nude group dynamics was too complex for the harmony pursued by Dalcroze's metricalism. Koch wanted people to move to ideas , to pedagogical dialogues, not just music. But his thinking was too complex for the Nazis as well, for they shut down his operations in 1933.