At the turn of the twentieth century, the spiritual and social movements Theosophy and later Anthroposophy became a strong source of inspiration for the pioneers of modernism and abstract art: Kandinsky, Mondrian, Malevich - and Hilma af Klint. In 1906, the Swedish artist began painting her first abstract series, Primordial Chaos, featuring blue, green and yellow geometrical shapes and spirals. Her main work, Paintings for the Temple, expresses what she calls the higher truth: unity beyond duality and the material world and mankind's spiritual evolution. What was the zeitgeist that inspired such an eruption in art? This anthology, based on a seminar held at the Guggenheim museum at the opening of their acclaimed exhibition Hilma af Klint: Paintings for the Future in October 2018, elaborates on this cultural phenomenon. Kurt Almqvist is President of the Axel and Margaret Ax:son Johnson Foundation for Public Benefit, where Louise Belfrage is a project manager. Daniel Birnbaum is the fomer Director of the Moderna Museet. Julia Voss is a Fellow at Lichtenberg-Kolleg, the Go?ttingen Institute of Advanced Studies. Tracey Bashkoff is Senior Curator, Collections and Exhibitions, at the Solomon R. Guggenheim.