Alois Riegl (1858-1905) was one of the founding fathers of modern formalist criticism. As a member of the Vienna School of Art Historians, he shared their range of interests in the decorative arts, art in transition, conservation and monuments. This collection of critical essays examines various facets of Riegl's work and opens with a new translation of Hans Sedlmayr's famous, and notorious, Die Quintessenze der Lehren Riegls. Included is Julius von Schlosser's assessment of Riegl's contribution to the Vienna School of Art Historians as well as essays by a team of international scholars. This book offers a re-engagement with the ideas of one of the most important and neglected art historians of the 20th century.