“The last 100 years have seen a constant battle against the concept of theatrical illusion: the idea that what we are watching is a plausible reproduction of reality. Everything has conspired against it,” wrote Michael Billington in 2012.

The phenomenon of dramatic and theatrical illusion, which was subjected to various forms of deconstruction in the twentieth century, seems to be inextricably bound up with the very European convention of simulating scenes of real life on stage in accordance with the social models and norms accepted at a given moment.

The effectiveness of theatrical illusion in the European theater tradition resulted not so much from the constantly improved, rich repertoire of staging and acting techniques as from, above all, the willingness of spectators to accept the dominant theatrical conventions. At various times, as Pierre Francastel noted, there have been various recipes for creating illusion. The effectiveness of illusion, in painting or the theater, depended after all on the “collectively accepted means of understanding reality.” Theatrical illusion depended, as Reginbald A. Foakes wrote, on “the activity of mind on the part of the spectator that distinguishes dramatic illusion from scenic illusion.”

In his French Dictionnaire du Theatre [Dictionary of Theatrical Terms], Patrice Pavis put forward just such a definition:

The fullest manifestation of the theater of total illusion was the naturalistic convention of the “fourth stage wall” at the end of the nineteenth century, permanently dividing two worlds—the theatrical work and the audience, who for the first time sat in the dark. Total illusion was assumed by the theater of August Strindberg, among others. As J. L. Styan encapsulates this postulate: “His audience was to be completely convinced of the reality of the world of the stage and transported wholly into its sphere of influence.”