Exhibitions of contemporary art have always confounded their viewers. By showing works that justifiably claim 'contemporaneity', they challenge us to rethink the traditional expectations of art. Hans Dickel presents the rapidly changing concepts of art since 1900 in their philosophical and socio-historical context. Using relevant art-theoretical source texts, the respective innovations in the concept of art are elucidated chronologically. The publication’s descriptions and analyses make it well-suited to all those interested in art. By characterising the various definitions of contemporary art, the aim is to reveal the diversity of artistic production and changing trends during the 20th and 21st centuries.