Fernand Deligny (1913-1996) has dedicated her life to work with "difficult children". His experimental projects with open-door institutions and instructors recruited from workers and unemployed people in the neighborhood, with reception networks for delinquent children and adolescents, as well as his first books, Seed of Crápula and The Effective Wanderers, quickly became a benchmark for the "special education" in France. Progressively, he moved away from the institutional system and in the 1960s spent some time at the famous La Borde Clinic, invited by Jean Oury and Félix Guattari. After that experience, he began his latest project: a network of shelters for autistic children that illuminated the reflections that appeared in The Arachnid and other texts. Seed de crápula (1945) is a kind of anti-manual pedagogy, made of aphorisms, anecdotes and advice, with equal doses of humor, irony and realism, aimed at forging the sensitivity of educators of all kinds that clash with the inefficiency of pedagogical idealizations and institutional coercions, in their daily task of cultivating the "seeds of evil". This edition is accompanied by contemporary texts by Argentine authors who have had diverse experiences in non-traditional teaching contexts (César González, Lost Toys Collective, Diego Valeriano).