Free True and False: Heresy and Common Sense for the Actor by David Mamet Page A

if you did “believe” them, it wouldn’t aid you in playing the scene. They, these “as ifs,” are just
reminders
, should you need them, to help you clarify to yourself the action in the scene.
    The action in this scene, remember, is to clean up a mess. That is the action, or the objective, you have elected in this scene. You no more have to feel like, or even
think
about, “My little sister has been caught shoplifting” than you have to feel like a sick horse when you meet the veterinarian.
    You have, in this simple analysis, used your powers of reason and of application to discover a simple, actable goal for yourself, which is
something like
that which the playwright devised for the character. The work you have done to arrive at such a goal has given you not only understanding but confidence, as you have applied yourself to things you can control.
    Because you have increased both your understanding and your confidence, you are less likely to be confounded or humiliated by an ignorant or arrogant director, or casting agent, should you encounter same. You have made a
choice
and, in so doing, have put yourself in the same situation as the protagonist.
    Horatio does not exist. But,
if
he existed, he, on the battlements, might feel fear of the ghost, might feel himself unprepared to quell the fears of Marcellus and Bernardo,
might
curse the fate which had elected him their military superior and, so, responsible for the situation.
    You
do
exist. When you are up—in an exposed position—not upon the battlements, but upon the stage—
you
might also feel unprepared, might feel you have made the wrong choice of an objective or of a career, might feel unequal to the task, might feel loathing for your fellow players.
    Everything you ever feel onstage will be engendered by the scene
. In rejecting a situation based on guilt (I can do
more
, do
better
, find a perfect solution, and, so, avoid uncertainty), in beginning with a frank avowal (I am confused, uncertain, and full of self-doubt), and proceeding honestly from one step to the next, you put yourself in the same position as the written character and can begin to bring to the stage the truth of the moment:
your
fear, uncertainty, self-doubt, courage, confidence, hardiness; yourself, in short, and your art.

CONCENTRATION
    T here is a fashionable pediatric diagnosis going around these days called attention deficit disorder. A friend remarked, “What a thing—in my day it used to be called daydreaming.”
    Now you, like everyone else, daydream. You dream of fame and fortune, of triumphal accomplishments and terrible misfortunes; you have, in short, an active, imaginative mind. You don’t have a very well developed power of what you have learned to call “concentration,” and the good news is that you don’t need it. For acting has nothing whatever to do with concentration. Perhaps you have read and studied and pondered Stanislavsky’s “circle of concentration,” in which you were asked to now enlarge, now constrain, your concentration, now to the room, now to the tabletop, now to your wristwatch, and so on.
    I know you have also done such exercises as the“mirror game” and have practiced concentrating on a past incident, feeling, or emotion, all with greater or lesser success.
    But success and failure in the above are equally irrelevant. Acting has nothing to do with the ability to concentrate. It has to do with the ability to
imagine
. For concentration, like emotion, like belief, cannot be forced. It cannot be controlled.
    Try this exercise: concentrate on your wristwatch.
    How did you do? Your ability to force your concentration lasted the briefest fraction of a second, after which you thought, “How long can I keep this up?” or, alternatively, “How interesting this all is, look how the hands go around!” which was, let us confess, hypocrisy—there was nothing interesting about it at all; you forced yourself to “concentrate,” and the result was