Final answer:
Constantin Stanislavsky believed that actors should live the life of their character on stage to create truthful and believable acting.
Step-by-step explanation:
Constantin Stanislavsky, founder of the Moscow Art Theatre (1898), believed that in order to create truthful and believable acting, an actor must fully immerse themselves in the life of their character on stage. Stanislavsky advocated for actors to go beyond superficial gestures and emotions and instead tap into the inner thoughts, intentions, and experiences of their characters. By living the life of the character, an actor can bring a level of authenticity and depth to their performances.