Explain briefly about the relationship between Macbeth and Lady Macbeth through out the story of Macbeth. Explain how does it change as the story...

In Acts I and II of Macbeth, Macbeth
and Lady Macbeth are integrated (share the same views) in their desire for power.  Their
marriage seems to be a practical means to a political end.  Neither have married, it
seems, for love or children.  Rather, they seem intent are being collaborative power
brokers, using the semblance of marriage for show.

Lady
Macbeth knows that women have no independent power in Medieval Scotland; instead, women
must live vicariously through their husbands.  Therefore, she resorts to motivating
Macbeth by any means necessary: she de-genders herself privately and calls out his
manhood publicly.  Then, she devises the plan to murder the king.  Taken together, she
becomes a persuasive accomplice, a validation of Macbeth's own secret desire, a Freudian
id who sways him from away from the guilt
of superego.  Lady Macbeth, however, cannot cross-over into the
violent world of men; she cannot stab Duncan herself, which shows that she needs Macbeth
more than he needs her.

In Act III, after Macbeth has
become King, the relationship changes from integrated to more segregated.  There is a
division of labor in the marriage.  Her front-end work done, Lady Macbeth dissolves into
the background and into mental illness.  Macbeth does not consult her in the murder of
Banquo; rather, he wants to surprise her with his own plan and execution.  Macbeth goes
on more killing sprees ("blood will have blood"), while Lady Macbeth cannot reconcile
her guilt over the murder of Duncan, perhaps because he looks too much like her
father.

While Macbeth continues to let his
id run amok in Acts IV and V, Lady Macbeth becomes a sleepwalking
superego, confessing her sins to her chamber-maid nightly.  In the
end, the blood and guilt are too much, and she uses suicide as the ultimate cleansing
agent.  Macbeth, though, is determined to fight to the death.  Herein lies a major
gender difference.  Having been deceived by the riddles and plans of women, Macbeth
resorts to what men do best: combat.  His unremorseless soliloquy and show of violent
defiance are but his final assertions of unadulterated manhood: he is no longer married
to woman, God, or country; instead, he is a free agent thane hell-bent on
nihilism.