This book examines one of the key notions of modernist architecture as it was formulated in Vienna at the turn of the twentieth century. Providing a close analysis of four major buildings - Olbrich's Secession Building, Hoffmann's Perkersdorf Sanitarium, Wagner's Postal Savings Bank, and Loos's Michaelplatz building - Leslie Topp investigates how 'truth' could be interpreted in a variety of ways, including truth to purpose, symbolist or ideal truth, and ethical notions of authenticity. Drawing on newly uncovered archival materials, Topp offers a new interpretation of familiar buildings that are shown to encompass utopianism, hyper-rationality, and subjectivism. She also explores the connections between Viennese modern architecture and contemporary painting, psychiatry, fashion, labor issues, and anti-Semitic politics.