Theatrical "doing" is not the same thing as regular walk-around-the-neighborhood "doing". Theatrical doing is significant, compressed in time and space and in pursuit of an objective. Theatrical reality is not the same thing as regular reality. Regular reality is what you get at the grocery store or local trattoria and it has zero theatrical currency. Stanislavsky pointed out that when you act you play an action in pursuit of an objective while overcoming an obstacle. The playing of the action is the "doing". If you stand on stage trying to convince the audience that you are experiencing emotion, then what you are "doing" is indicating. Face acting. And that is an acting error.
Occasionally in one of my scene study workshops, an actor will present a scene in which she is struggling to remember her lines. In such an event, what she is, in reality, "doing" is trying to remember her lines. She is doing that while she simultaneously tries to trick the audience into believing that she is in pursuit of a theatrical objective. But audiences are very smart. They see what you are doing and it is unwise to condescend to them in this fashion.
The "doing" in acting is as concrete an activity as the hammering of a nail into the wall or the changing of a tire. It is physical and active and it has a purpose. Actors are not novelists. They do not describe action; they actually "do" the action. It isn't enough to analyze an action or to know in your head what you should be doing if you are not going to actually "do" it. Acting happens in the fleeting and present moment. This is one of the distinguishing characteristics of the art form in fact.
To further cause frustration for a new actor, the dialogue in a script does not always make it clear what a character is "doing", and it may even purposely mislead. A character might be talking about the weather with the postman when he is in fact planning a bank robbery. He might appear to be hanging out in a clearing when he is in fact busily waiting for Godot. Remove Godot from the equation and you have something boring theatrically. Hamlet instructs the players on the points of fine acting not because he is an enthusiast for acting as an art form but because he is setting a trap.
It is worth mentioning, too, that stage "business" should not be confused with "action". I saw an actor on stage last week pouring himself a drink of whisky. I asked him afterward why he did that, and he didn't have a reason other than it was drink time. I explained that drinking whiskey in the context of his particular scene could be justified as an attempt to calm his nerves. He was pouring the drink so as to look busy. It was a counterfeit action. He was pitching and filling on stage rather than playing an action in pursuit of an objective.
Let me say it one more time: Action on stage is significant. It is not regular reality. It is not enough for an actor to be "real" and "truthful". Acting is story telling, a shamanistic activity. It is purposeful. It is necessary when you are on stage to be playing an action in pursuit of an objective one hundred percent of the time. Acting is doing.
