Bruno Queysanne presents some of his research concerning the conflict between the philosopher Ludwig Wittgenstein and the architect Adolf Loos. He discusses the view that anything added to a building that is not part of its structure diminishes it as a work of architecture. He argues that Wittgenstein’s house for his sister doesn’t reflect Wittgenstein’s work in philosophy. Queysanne characterizes the house’s lack of cladding outside, and the abundant cladding inside seems to suggest agreement with Loos’ and Gottfried Semper’s argument that cladding is the true origin of architecture instead of the structure. Queysanne compares Wittgenstein’s plan for his sister’s house with the plan created earlier by the architect Paul Engleman. Wittgenstein was so committed to avoiding any kind of ornamentation that he excluded necessary structural elements in order to maintain a pure form. Turning to Loos, Queysanne argues that Loos strove to charge a space with feeling so that the structure would recede to the background. The Villa Muller’s exterior is similar to the Wittgenstein house in its minimal exterior, but achieves meaning absent in the Wittgenstein house through the protective metal at the top the walls, a type of cornice. He discusses some provocative details of the interior of Loos’ Villa Muller: textile used as marble, furniture that is part of the structure, openings that connect spaces.