This sourcebook features a compilation of texts that are key to understanding and interpreting Walther's objects, and to assessing the cultural impact of an artist who in 1960s and 1970s willfully chose not to form part of any established group or art movement, focusing instead on reformulating the relationship between art and action in order to investigate the use of space, time and language as work materials. Text: Eugenio López Alonso, Bazon Brock, Yve-Alain Bois, Julieta González, Christian Rattemeyer, Franz Erhard Walther, Peter Weibel, a.o.