The modern era in the theatre is remarkable for the extraordinary role and influence of theoretical practitioners, whose writings have shaped our sense of the possibilities and objectives of performance. This study offers a critical exploration of the theoretical writings of key modern practitioners from Stanlislavski to Boal. Designed to be read alongside primary source material, each chapter offers not only a summary and exposition of these theories, but a critical commentary on their composition as discourses. Close scrutiny of the cultural context and figurative language of these important, and sometimes difficult, texts yields fresh insight into the ideas of these practitioners.