Adolf Franz Karl Viktor Maria Loos (1870 - 1933) was an Austrian and Czech architect and influential European theorist of modern architecture. His essay Ornament and Crime advocated smooth and clear surfaces in contrast to the lavish decorations of the fin de siècle and also to the more modern aesthetic principles of the Vienna Secession, exemplified in his design of Looshaus, Vienna. Loos became a pioneer of modern architecture and contributed a body of theory and criticism of Modernism in architecture and design and developed the "Raumplan" (literally spatial plan) method of arranging interior spaces, exemplified in Villa Müller in Prague.