Is Lady Macbeth Macbeth's fourth witch?Please justify with quotes from the text.
Well, she certainly isn't a witch to start with. And she doesn't have any supernatural powers, either. How do we know? Because in Act 1, Scene 5, she openly worries about Macbeth's nature, and worries that he won't be ambitious enough to actually get himself the crown and make the witches' prophecies come true:
Yet do I fear thy nature;
It is too full o’ the milk of human kindness
To catch the nearest way.
Lady Macbeth knows she's got to persuade him. So she actually calls on evil spirits to make her evil:
Come, you spirits
That tend on mortal thoughts, unsex me here
And fill me, from the crown to the toe, top-full
Of direst cruelty! ...
Come to my woman's breasts,
And take my milk for gall, you murdering ministers,
Wherever in your sightless substances
You wait on nature's mischief!
She wants to be cruel - and it happens. She can persuade him. But there's no magic. She isn't actually a witch.
She is like them in one important way though. Lady Macbeth does persuade Macbeth to continue with the plot later - but, like the three sisters, she doesn't do anything herself. She just persuades him to do it. She isn't literally a witch - but like the witches, she pours her ideas into Macbeth's area, affecting the play's key battleground: Macbeth's brain.
Not literally, no. But she is manipulative, power-hungry, and cruel.
even though lady macbeth changes psychologically throughout the text and she seems adamant about what should be done(especially about killing duncan), and calls upon evil spirits to "unsex" her, she is not quite literally a witch. her behaviors just seem unnatural