Invention operates at the centre of artistic identity. As an important and almost intangible element of the architects capacities, it often remains unsaid or unspoken. Invention denotes the moment where the genius of the architect-artist surfaces. Moreover, invention is one of the few terms that bridges the janus-faced identity of the architect who is at once artist and engineer. In both these fields the issue of invention is regarded as crucial. This issue of OASE investigates specific moments when -designers discover new forms of expression. In Western Europe and in modern times (since the eighteenth century) this idea of invention has been generally understood as break with -traditional forms. Hence, the history of modern architecture describes these moments of invention as leading to a new -formal paradigm or style that is often shared by a school or artistic tendency. Oase 74 offers a series of studies of ‘moments of invention’ out of the post 1945 history of architecture. Architectural projects by Hans Scharoun, Norman Foster, Alejandro de la Sota and Fernand Pouillon are discussed. In addition this issue presents a series of interviews with contemporary architects (Gigon & Guyer, Xaveer De Geyter, Neutelings & Riedijk) that place the invention of new typological and tectonic solutions at the heart of their design practice.