All the theories that acting is reacting to imaginary circumstances as though they are real, and directing is turning psychology into behavior, those are all stabs at something that can't be taught. All the great actors can't talk about what they do, and they don't want to begin to talk about it. They just do it.
Once in awhile, there's stuff that makes me say, That's what theatre's about. It has to be a human event on the stage, and that doesn't happen very often.