The notion of a theatre implies, at the absolute minimum, a specially marked space, a bounded if not enclosed arena, which holds within it a second (stage) space for the “play” or representation. The double meaning of “play” highlights some of the key concepts involved here. The “play” set on a stage has a certain closure, as with games, where the physical or simply “ideal” limits (e.g. the bounds, the rules) determine the space of play. Within the theatre, the “playing” space differs from that which is outside the theatre by two equal rotations, and by virtue of this double difference the stage partakes of an ambiguous equivalence with the first term of comparison, “reality.” Ortega y Gasset was on target and characteristically lucid in his description of theatre along these lines in the more or less phenomenological idiom of his “Idea del teatro”: the theatre is a visible metaphor, a locus of transformation, a place where, because of these double differences, the seeing and the seen become interchangeable. Working beyond phenomenology, Antonin Artaud, and Jacques Derrida writing on Artaud, would account for the paradoxical status of the elements of theatre in terms of the successive displacements and deferrals by which the marked space is at once equivalent to and yet different from “reality”: “Closure is the circular limit within which the repetition of difference infinitely repeats itself. That is to say, closure is its playing space.”