Who is Antoine Artaud, Merce Cunningham, Samuel Beckett, Jerzy Grot from The Empty Space and what is their importance?

These four artists are contemporaries of the author whose work he cites as examples of ways in which the rough theatre strives to express something holy (see "Objects/Places—Rough Theatre" and "Holy Theatre"). Their work is portrayed by the author as functioning in an opposite way to that of Shakespeare and Chekhov (see below), in that their emphasis is on the rough—on the impulsive and instinctive as a source for spiritual truth.