In this lecture performance, the "ungiven" is conceived as an opening - a dialogical horizon of possibility. This opening is not understood as entry into a locatable space in which encounter takes place; rather, it names a non-localizable access to what remains unknown and potentially unsettling. It resembles the moment of taking a step without knowing what will carry it: an act that involves risk, exposure, and the possibility of opening up to something new. The paper asks whether such an opening can be understood and practiced as a performative mode. Performativity is conceived as a mode of enactment in which meaning emerges through the act itself. A performative act produces conditions under which something becomes operative without being fully given, determined, or conceptually graspable. In this sense, performativity is structurally bound to the ungiven: what remains indeterminate is not a deficit, but a constitutive element of the act. Both aesthetic and religious experiences are understood as performative insofar as they unfold through exposure, temporality, and risk, rather than through the possession of stable meanings. Drawing on Umberto Eco's concept of the opera aperta, aesthetic experience is approached as an open and relational process in which meaning remains provisional and contingent. This openness is intensified in performative practices, which - following Dieter Mersch - can be understood as events of showing that resist representational closure. The paper asks whether both aesthetic and religious experiences open dialogical spaces by suspending closure and exposing subjects to what cannot be fully given? Dialogue, in this sense, is not grounded in shared concepts or doctrinal agreement, but arises as an experiential mode of relating to indeterminacy. The ungiven thus functions as a dialogical horizon - a productive interval that enables encounter, transformation, and ongoing exchange without resolution. - RELIGION IN DIALOGUE WITH THE ARTS -