I need help analyzing this quote from Macbeth.
When part in the play does this take place? And what is the explanation of the quote?
Lady Macbeth (1.5. 38-41)
"Come you spirits that tend on mortal thoughts, unsex me here and fill me here, and fill me from the crown to the toe, top-full of direst cruelty! Make think my blood."
This quote from Shakespeare's Macbeth comes after Lady Macbeth has received a letter from her husband and before he arrives at the castle himself.
The letter details the predictions made by the weird sisters, and informs Lady Macbeth that one of the predictions has come true: Macbeth has been made Thane of Cawdor. The second prediction is that Macbeth will be king.
Lady Macbeth is extremely ambitious, as is her husband, and in her speech after she reads the letter she questions whether or not her husband is ruthless enough to do what's necessary to obtain the throne--kill Duncan.
The section of the speech you quote above is in a speech that's given just a few minutes later and shows Lady Macbeth preparing herself to be ruthless. She wants to be the stereotypical male, aggressive and ruthless, masculine. The famous line, "unsex me here" is Lady Macbeth asking to be rid of any female qualities, such as gentleness and pity. She wants to be filled with cruelty, and wants her blood to be made thick. The idea of the thick blood is that thick blood will stop those same female qualities from reaching her mind.
In summary, then, Lady Macbeth asks the "spirits" to strip away female qualities and replace them with male qualities, those qualities that will enable her to be ruthless enough to assassinate King Duncan.
This apostrophe by Lady Macbeth is by far the best scene in Act I. After she reads Macbeth's letter that prophesies of him becoming king, she walks upon her ramparts and speaks to the "spirits that tend on mortal thoughts" to completely remove her human qualities; this notion is revealed in the request to be "unsex[ed];" she wants to be neither a man nor woman, for both sexes have consciences, and she doesn't want one, for it will potentially inhibit her from her desire, which is to kill Duncan so that Macbeth can become king. The fact that she wants to be some kind of evil creature who does not have a conscience can be seen in her request that the spirits "make thick [her] blood. If her blood is thick, then she is dead, and if she is dead, she becomes some kind of spirit. The spirit that she desires to become is one that is filled with a "direst cruelty." This soliloquy reveals her nefarious ambition.
You have told us yourself where in the play this happens. At this point in the play, Macbeth has already heard the witches' prophecies about him. He has already been made Thane of Cawdor. But he is not yet king. The king, Duncan, is coming to visit Macbeth's castle.
In this quote, Lady Macbeth is wishing to be "unsexed" so that she could be more cruel and power hungry. This refers to the idea that women should not have these traits. But she thinks that her husband will not be ruthless enough to do what he needs to become king. So she wants to be ruthless enough to push him to kill Duncan.