Since the fifties, Geert Bekaert has written consistently and continuously on architecture and the arts. With this research, I want to enlighten the (architectural) theory of Geert Bekaert, by reconstructing it within the international landscape of architecture theory and history. In Bekaert’s thinking, architecture is the first and most comprehensive human activity it precedes ideology, politics, aesthetics, economy and philosophy. Architecture constructs the reality in which human life and the history of humankind can be developed. In my thesis, I will expand and clarify this ‘basic’ aspect of architecture – and this fundamental critical theory.