In The Crucible, discuss how a protagonist's primary motivation changes throughout the drama.

The easiest example of this would be John Proctor.  Yet, I
think that the change that Elizabeth Proctor undergoes throughout the drama is as
powerful, if not more than that of her husband.  On one hand, Elizabeth starts out the
drama in an emotionally challenging relationship with her husband and cannot see past
her own condition.  The early stages of the play display Elizabeth's emotional
motivation as protecting her own life and her own notion of the good.  It is for this
reason that both she and her husband cannot speak of Abigail's accusations without an
undercurrent of mistrust and skepticism, given what happened in their own marriage. 
Yet, throughout the course of the play, as the town devolves into greater madness,
Elizabeth recognizes a larger element at stake.  Her desire to remain inward is
impossible as the accusations reach a fevered pitch.  She is forced to take the stand
and her motivation changes in that while she lies to protect her husband, she also
understands his good nature.  Elizabeth's fear and emotional frigidity melts as the play
progresses.  It is interesting to note that while the town ends up becoming
progressively worse, the relationship between Elizabeth and John strengthens, with both
of them trusting one another more and being able to turn to the other in a more open
manner.  This is completed when John recognizes that he must stand for the truth and
Elizabeth no longer protests.  It is at this point that Elizabeth's motivation has
transcended beyond her own condition and rather towards an idea.  Being the perfect
wife, the perfect soul mate, or even in acknowledging the goodness of her husband
becomes her motivation.  When she says, "God forbid I take it from him," in speaking
about John's sense of honor and commitment to the truth at the end of the play as he
walks towards his death, Elizabeth's motivation is clear to all as she has become a
transcendent figure who stands for values that are permanent and beyond what is
happening in Salem.