Konstantin Stanislavski was a Russian acting teacher during the early twentieth century. He developed and defined an innovative style of acting and performance that was grounded in realism. His teachings later became the basis of the American theory and practice known as The Method. Stanislavski taught that a character's life must be lived on stage as if it were being lived in life, and that actors must create the life of their character by immersing themselves in the character's experiences.
Brecht on Theatre: The Development of an Aesthetic