Jean Arp, the German-French modernist, helped define both Dada and Surrealism. His practice challenged conventional ideas of representation, looking instead to forms and processes of the natural world. This September, Hauser & Wirth presents “Arp: Heads or Tails,” the first New York exhibition devoted to the artist in nearly 15 years. Drawing on significant works from across his career, it examines his sustained interest in transformation. Nature offered Arp an alternative to an increasingly mechanized age, and he made forms that gave shape to natural forces—clotting, hardening, congealing, fusing—and, through them, to the cycles of growth, reproduction, transformation, and decay. The exhibition coincides with the monograph Arp: Paper, just released by Hauser & Wirth Publishers, which surveys over 200 works on paper, many of which have never been exhibited. —Clara Scholl