In Shakespeare's Hamlet, why does Ophelia say this, in Act Four, scene five?
"By Gis and by Saint Charity/Alack and fie for shame/ Young men will do't if they come to't-/By Cock, they are to blame./ Quoth she, 'Before you tumbled me/You promis'd me to wed'. He answers, "So would I a done, by yonder sun, And thou hadst not come to my bed''.
It is slightly odd because her other songs in Act sc 5 are about the death of her father (29-32) and his burial (lines 37-40). As the Queen is hearing this, it must be important. What triggers Ophelia to say this because it seems like something Hamlet would say?
In Shakespeare's Hamlet, by the time Ophelia is singing the snippet in Act Four, scene five, she has lost her mind. As she rambles on, she has visions of her father, his death and Hamlet's rejection running through her addled brain.
As the Queen enters, she is told that Ophelia is mad. Gertrude really doesn't want to speak to her, but one of the men at court advises her to pity the young woman. So Gertrude asks what Ophelia needs.
She speaks much of her father; says she hears
There's tricks i' the world, and hems, and beats her
Spurns enviously at straws; speaks things in doubt,
That carry but half sense. Her speech is nothing,
Yet the unshaped use of it doth move
The hearers to collection; they aim at it,
And botch the words up fit to their own thoughts;
Which, as her winks and nods and gestures yield them,
Indeed would make one think there might be thought,
Though nothing sure, yet much unhappily. (5-15
In essence, the man reports that Ophelia speaks of her father, infers that she has heard there is trickery in the world (could she be referring to Hamlet, or Polonius, or Claudius...or all three?); he notes the she makes no sense. The way she speaks makes one want to understand her based on what they think she means, but it's only clear that she is unhappy.
Gertrude speaks to the girl, and Ophelia wonders how she can tell her (the Queen's) one love from another—by his clothes? One would assume this may be an allusion to her hasty marriage to Claudius, and that both men dress similarly. Ironically, she may be pointing out her foolishness thinking the men are equal.
How should I your true love know
From another one?
By his cockle hat and staff
And his sandal shoon. (27-30)
Ophelia speaks of one dead buried. Claudius believes she speaks of her father.
Say you? Nay, pray you, mark.
He is dead and gone, lady,
He is dead and gone;
At his head a grass-green turf,
At his heels a stone.
O, ho!) (32-37)
This is one of the only scenes in the play where the audience may actually find something of value in Claudius. He seems genuinely fond of Ophelia. When she talks in the section you have mentioned, note that Ophelia speaks the first section of this bawdy song, and Claudius—with seeming gentleness—finishes it for her.
Indeed, without an oath, I'll make an end on't!
By Gis and by Saint Charity,
Alack, and fie for shame!
Young men will do't if they come to't
By Cock, they are to blame.
Quoth she, 'Before you tumbled me,
You promis'd me to wed.'
'So would I 'a' done, by yonder sun,
An thou hadst not come to my bed.' (63-71)
Ophelia complains that men think with their lust and not with their brains. She sings a verse where a maid says that before she slept with the man she loves, he promised he would marry her; Claudius finishes the line in which the lover asserts—swearing by the sun—that he would have married her even if she had not slept with him.
Shakespeare is using this vulgar song in Ophelia's madness to blame Hamlet for his treatment of her. He did not sleep with her and leave her, but he did make promises. In Act One, he had just told her that he loved her. And while Laertes warns her away from Hamlet, at her grave, Gertrude says she had had hopes the two would marry.
Hamlet's betrayal is not physical but mental and emotional. Shakespeare points out that Hamlet could have trusted her rather than rejecting her, which moves her madness along.