The debate over the design thesis is often entangled in the dialectics of the practical and the theoretical. Whether the argument is waged and weighted in favour of a practical emphasis or a theoretical emphasis, or more insidious, a judicious balance between the two, what is inevitably assumed in the debate is the possibility of drawing and/or locating a dividing line between the practical and the theoretical. This article explores the inherent contradictions of this dichotomy, that make the traditional definition of thesis--a theorem or a hypothesis regarding the nature of the phenomenon under investigation--a problematic definition for architecture. Inasmuch as architecture is, in each iteration, a cultural construct, it is always and already the formal expression or embodiment of a theory. To avoid the tautology of positing a theorem about a theorem or a hypothesis regarding a hypothesis, the design thesis may be defined, not as a theorem or a hypothesis, but as an analytical posture assumed or a critical stance taken on the theorem that is or should be the phenomenon under investigation. In this case, the question to ask at the outset of a design thesis is not what patent "theory" should the proposed building speak of, but what arcane theory does its type historically hide under the rubrics of "function" or "practical" requirements? It must begin, in other words, by de-familiarising the familiar.