If you are to do justice to [the great roles], you must fly up to them - rather than dragging them down to you - by expanding your range of knowledge and strengthening your imagination. Your imagination must become as real to you as your memories and feelings. What you take into yourself about psychology, politics, sociology, history and so on, will allow you to reach places in yourself you didn't know existed. No line, no image, no thought can be left general. Each must be specific and personal. Your work is not complete until this is so.