The doctoral dissertation examines the collaborative efforts of different international groups based in France – such as the Salon des Réalités Nouvelles, Groupe Espace, and the Internationale Situationniste – which advocated a “synthesis of the arts” in the years that followed the Second World War. My work considers a wide range of projects, from the collective decoration of monumental buildings to temporary installations in galleries by way of outdoors art exhibitions and theatrical performances. I seek to answer a set of general questions: How exactly did the "synthesis of the arts" discourse lead to a rethinking of public space in postwar France? How did it participate to the physical reconstruction and modernization of French cities? How did this discourse, that challenged the notion of artistic autonomy as the precondition of genuine aesthetic experience, contribute to forming new forms of spectator involvement and public address? Finally, how did it relate to the shifting priorities of official French cultural institutions in the middle decades of the twentieth century in regards to the integration of modern art to the built environment? I argue that the different proponents of a "synthesis of the arts" reterritorialized the language of artistic abstraction developed in the 1910s and 20s into a spatial paradigm that would directly engage with everyday life by creating purportedly unified and immersive environments, what were called “spectacles plastiques”. Such spectacles were shapeable performative events in which individuals were mobilized and invited to communally share an embodied aesthetic experience. The "synthesis of the arts" was also an attempt to move away from Germanic notions of Gesamtkunstwerk, or “total work of art”, tainted as they had become with various types of totalitarian regimes in the 1930s. Some of the artists and architects considered include Le Corbusier, F. Léger, F. Del Marle, N. Schöffer, G. Debord and Constant.