Modern drama differs dramatically from the pre-twentieth-century theater. It rejects the conventions of "realistic" restrictions of time, place, and action.
Through the ages there have been changing standards of what was acceptable in the theater. Traditional Aristotelian unities were still considered valid by many European authorities even as late as the eighteenth century. In the Preface to his edition of Shakespeare, published in the 1760's, Johnson argued that the unities weren't valid. This was in answer to those who viewed Shakespeare's non-observance of them as a defect in his plays. At the time it was still asserted by theatrical "purists" that a play's action should fall within a twenty-four hour period and have a limited setting. By the nineteenth-century, most dramatists no longer felt the need for these restrictions. A general sort of realism
was still the norm. For example, Ibsen's plays, though they are path-breaking in their way, could take place in "real life." There is nothing absurd or fantasy-like from a naturalistic perspective.
We don't need to look at the extremes of the Theater of the Absurd in the twentieth century to see that standards had changed even in dramatic works that were basically realistic. In the play Strange Interlude, for instance, O'Neill has his characters speak their "thoughts." It's like a voice-over on stage, and places the audience in meta-dimension beyond what is depicted in the drama. In Death of a Salesman
, Miller blurs the distinction between fantasy and reality, past and present. The action flits back and forth between what is actually taking place in the present and Willy Loman's memories and dreams. His brother Ben is a recurring presence on stage, although Ben is not really present during the action. Things that happened years earlier are woven into the drama.
All of this builds up the picture of Willy as a man who has been a failure constantly throughout his life. In a naturalistic drama it would not be possible for the playwright to depict Willy Loman's life story so completely. The more absurdist tendencies show how Willy's past, and his fantasies, constantly impinge upon the present. The fluid shifts in time and space are emblematic of Willy's distorted thoughts. But such instability becomes, in the hands of Miller and other modern playwrights, a standard technique of drama. The stage has become a mental arena in which, there are no limitations based upon what could take place in real life.