In Part I, the basic ontology of theatre is described. A theatre per se is a setting designated or prepared for a performance. It functions by bracketing-off and drawing attention to what is performed, and setting it aside from the surrounding reality. However, this bracketing-off also signifies that what is happening is enclosed in the sense of being a selective interpretation of experience. We can read a protagonist’s inner thoughts in a novel or even a poem. In the play, however, the actor presents them before us. The character is there in direct perception rather than through the imaginatively intended vehicle of the read text. Our understanding of what the playwright has written will be inseparable from the particular way in which the artist interprets his or her role, from the Director’s guidance of this, and from the playwright’s gifts of language and narrative composition. This creates a unique and extremely complex image of life. In Part II, the theory is discussed in relation to Aeschylus’s Oresteia trilogy and Georg Buchner’s Woyzeck, and, in Part III, by reference to Shakespeare’s Hamlet.