Margareta Ingrid Christian unpacks the ways in which, around 1900, art scholars, critics, and choreographers wrote about the artwork as an actual object in real time and space, surrounded and fluently connected to the viewer through the very air we breathe. Theorists such as Aby Warburg, Alois Riegl, Rainer Maria Rilke, and the choreographer Rudolf Laban drew on the science of their time to examine air as the material space surrounding an artwork, establishing its “milieu,” “atmosphere,” or “environment.” Christian explores how the artwork’s external space was seen to work as an aesthetic category in its own right, beginning with Rainer Maria Rilke’s observation that Rodin’s sculpture “exhales an atmosphere” and that Cezanne’s colors create “a calm, silken air” that pervades the empty rooms where the paintings are exhibited. Writers created an early theory of unbounded form that described what Christian calls an artwork’s or its ability to stray outside its limits and engender its own space. Objects viewed in this perspective complicate the now-fashionable discourse of empathy aesthetics, the attention to self-projecting subjects, and the idea of the modernist self-contained artwork. For example, Christian invites us to historicize the immersive spatial installations and “environments” that have arisen since the 1960s and to consider their origins in turn-of-the-twentieth-century aesthetics. Throughout this beautifully written work, Christian offers ways for us to rethink entrenched narratives of aesthetics and modernism and to revisit alternatives.