This article examines the relations between design of the stage and the scenography, particular of what we somewhat loosely refer to as "modern" theatre. I will set out by presenting three inter-related principles regulating the processes of perception and interpretation of space/scenography in the theatre. The first principle draws attention to the hybrid semiotic modeling of the stage space, based on the one-point linear perspective developed by the Baroque tradition, using both two-and three-dimensional principles of representation; the second focuses on the entrances, the presences and the exits of human and in particular of the non-human agents to, in and from this hybrid scenographic space; and the third examines the hermeneutic strategies and the philosophical concerns activated by the two first principles, in particular through the audience perception and interpretation of the human/non-human split communicated by a specific performance. My basic claim is that the theatre enables the spectators to measure and evaluate their own humanity (physically, emotionally and ethically) in relation to this human/non-human divide, in particular through the entrance of supernatural and divine figures into the hybrid container of the stage, but also by their absences. This sense of humanity must finally be considered in relation to the still constantly recurring failures in the world around us today, as well as in history to grasp and to express what we perceive as our own truly human proportions. After presenting these claims, I analyze Bertolt Brecht's representations of space in his own productions of Life of Galileo.