Helio Oiticica (1937-80) was one of the most brilliant Brazilian artists of the 1960s and 1970s. He was a forerunner of participatory art, and his melding of geometric abstraction and bodily engagement has influenced contemporary artists from Cildo Meireles and Ricardo Basbaum to Gabriel Orozco, Dominique Gonzalez-Foerster, and Olafur Eliasson. This book examines Oiticica's impressive works against the backdrop of Brazil's dramatic postwar push for modernization.From Oiticica's late 1950s experiments with painting and color to his mid-1960s wearable Parangols, Small traces a series of artistic procedures that foreground the activation of the spectator. Analyzing works, propositions, and a wealth of archival material, she shows how Oiticica's practice recast-in a sense "e;folded"e;-Brazil's utopian vision of progress as well as the legacy of European constructive art. Ultimately, the book argues that the effectiveness of Oiticica's participatory works stems not from a renunciation of art, but rather from their ability to produce epistemological models that reimagine the traditional boundaries between art and life.