ON ACTING: Freedom Within Limitations
The great pianists Horowitz, Rubenstein, Paderewski and Liszt played within the most rigid pre-set musical score of a single Bach, Mozart or Beethoven composition, i.e., without changing a note, but their piano playing always remained distinctive and free. They were able to retain their individual selves in spite of very strict formal demands.
Good actors can achieve the same results, with practice and experience. A wonderful definition of maturity is: learning to live freely and spontaneously within limitations.