If the notion of complete, perfect, and permanent architecture is a fallacy, how have we come to expect a building to be complete when construction is finished and to wish a building to remain perfect permanently? Furthermore, what assumptions have we made and what implications have we accepted along the way?We must go back more than five centuries to find the root of the fundamental way in which we regard architecture. De re aedificatoria is the architectural treatise written by the Renaissance humanist polymath Leon Battista Alberti, who presented it to Pope NicholasV in 1452. In the second chapter of its sixth book,Alberti defines beauty by concinnitas.This definition, familiar to many architects and architectural students, reads: “Beauty is that reasoned harmony of all the parts within a body, so that nothing may be added, taken away, or altered, but for the worse” (Alberti 1988, 156).