The queen his mother
Lives almost by his looks, and for myself—
My virtue or my plague, be it either which—
She’s so conjunctive to my life and soul,
That, as the star moves not but in his sphere,
I could not but by her. The other motive
Why to a public count I might not go,
Is the great love the general gender bear him,
Who, dipping all his faults in their affection,
Would, like the spring that turneth wood to stone,
Convert his gyves to graces

In Act 4, Scene 7, Claudius explains to Laertes the two reasons why he cannot publicly rebuke Hamlet for killing Polonius. The first, he says, is because he cannot live without his wife, Gertrude, and she is devoted to her son, Hamlet. His “other motive” for not having yet acted against Hamlet is purely political. The public loves Hamlet too—far more than it loves him, Claudius implies—and it if he were to move against him, it would only make Hamlet more popular. The first reason is superficially about his wife, but in fact, both reasons he gives are about the impact his publicly moving against Hamlet would have on himself.

Laertes, was your father dear to you?
Or are you like the painting of a sorrow,
A face without a heart?

As the cunning and manipulative Claudius begins to hatch his plan to remove Hamlet as a threat to his throne in Act 4, Scene 7, he tests Laertes by asking him if he truly mourns his father or if his public displays of mourning are all for show. Laertes, whose mourning is real and whose sorrow has been increased by his sister’s decent into madness, responds to Claudius’s question with incredulity that Claudius could even ask such a question. You can read more about this quote in Quotes by Character: Claudius (the fifth quote).

Not that I think you did not love your father
But that I know love is begun by time,
And that I see, in passages of proof,
Time qualifies the spark and fire of it.
There lives within the very flame of love
A kind of wick or snuff that will abate it.
And nothing is at a like goodness still.

After Laertes tells Claudius that he’s shocked that he would question his devotion to his slain father, Claudius follows up with this quote as he continues to lay the groundwork for using Laertes in his plan to bring down Hamlet. In the process of doing so, he delivers what turns out to be a thoughtful speech about the human tendency of having strongly held beliefs and commitments cool and fade over time.

Her clothes spread wide,
And mermaid-like a while they bore her up,
Which time she chanted snatches of old lauds
As one incapable of her own distress,
Or like a creature native and indued
Unto that element.

As Claudius and Laertes are working out their plan to kill Hamlet, Gertrude interrupts them with the sad news that Ophelia has drown. Here, in one of Shakespeare’s most moving uses of imagery, Gertrude vividly describes the drowning, painting an indelible image of Ophelia calmly singing hymns as her clothes briefly keep her aloft “mermaid-like” while the water carries her to her death.

Too much of water hast thou, poor Ophelia,
And therefore I forbid my tears. But yet
It is our trick. Nature her custom holds,
Let shame say what it will. When these are gone,
The woman will be out.—Adieu, my lord.
I have a speech of fire that fain would blaze,
But that this folly doubts it.

In this sad and heart-felt speech, Laertes tires to react stoically and (as he implies) like a man to the news of his beloved sister’s drowning but finds that he cannot because he is overwhelmed by grief and emotion. He says that he doesn’t want to shed tears (and quips that Ophelia has had enough water already), but that it’s just human nature to cry in such sad situations. He then vows that after he stops crying (which he references as a womanly act), he will return and follow through on the plan that he and Claudius have been discussing (to kill Hamlet).