Stanislavski created a role using his logical mind– as opposed to the artist right brain. He engaged in a series of logical questions to break down the motive and understand the character’s actions and feelings.
He describes his method in his book, Creating a Role.
“What are the circumstances of my inner life. What are my personal living thoughts, desires, capacities? If I am a woman, how am I related to the other character in this scene?”
Those questions in the minds of his characters made those characters spring to life. His method of teaching acting shaped the American stage and film studios for most of the twentieth century. I suspect more than a few writers have used the same techniques to create a living character in their novels.