7. why does lady macduffs son say liars and swearers are fools?

My dearest cousin, I beg you, control yourself. Your husband is noble, wise, and judicious, and understands the current political unrest. I don’t dare say anything more than this, but it is a bad time when people are denounced as traitors and have no idea why; when we believe rumors out of fear, but aren’t even sure what we’re afraid of. It’s like floating in a wild ocean storm, being tossed all around and getting nowhere. I must leave now, but it won’t be long before I return. When things are at their worst they must eventually end, or else improve to be like how they were before. My good cousin, I give my blessing to you.

Macduff’s wife. She is upset by her husband’s sudden flight to England, which she sees as an abandonment that leaves her and their children in danger.

Ross

7. why does lady macduffs son say liars and swearers are fools?

A thane and family friend of the Macduffs. He tries to reassure Lady Macduff that her husband means well and that she is safe.

Son

7. why does lady macduffs son say liars and swearers are fools?

Macduff and Lady Macduff’s young son, who has a smart mouth. He has more faith in his father’s intentions.

Messenger

A messenger who has defected from Macbeth’s service to warn the Macduffs of the impending attack.

Murderers

Killers-for-hire in Macbeth’s employ, sent to kill the Macduffs.

Scene Summary: 

Macduff’s wife, Lady Macduff, questions Ross about her husband fleeing to England. She doesn’t understand why he would leave his family defenseless at a time like this. Ross tries to reassure her, but no sooner does he leave than a messenger arrives to tell Lady Macduff and her son to run for their lives. But it’s too late—the murderers have arrived, and they kill her son. She flees, the murderers hot on her heels.

At Fife, in Macduff's castle, Lady Macduff is lamenting to Ross that her husband has run away, which, sure makes him look suspicious. Also, abandoning your family with no defense is seriously uncool. 

ROSS My dearest coz,
I pray you school yourself. But for your husband,
He is noble, wise, judicious, and best knows
The fits o’ th’ season. I dare not speak much 20
further;
But cruel are the times when we are traitors
And do not know ourselves; when we hold rumor
From what we fear, yet know not what we fear,
But float upon a wild and violent sea 25
Each way and move—I take my leave of you.
Shall not be long but I’ll be here again.
Things at the worst will cease or else climb upward
To what they were before.—My pretty cousin,
Blessing upon you. 30

LADY MACDUFF
Fathered he is, and yet he’s fatherless.

ROSS
I am so much a fool, should I stay longer
It would be my disgrace and your discomfort.
I take my leave at once. Ross exits.

It's cool, Ross says. Macduff had his reasons. He can't explain to Lady Macduff, but he assures her Macduff had to do what he had to do. These are tough times. Yeah, thanks, says Lady MacD. Check out my son, here: he has a dad, and yet it's like he's fatherless.

LADY MACDUFF Sirrah, your father’s dead. 35
And what will you do now? How will you live?

SON
As birds do, mother.

LADY MACDUFF What, with worms and flies?

SON
With what I get, I mean; and so do they.

LADY MACDUFF
Poor bird, thou ’dst never fear the net nor lime, 40
The pitfall nor the gin.

SON
Why should I, mother? Poor birds they are not set
for.
My father is not dead, for all your saying.

LADY MACDUFF
Yes, he is dead. How wilt thou do for a father? 45

SON Nay, how will you do for a husband?

LADY MACDUFF
Why, I can buy me twenty at any market.

SON Then you’ll buy ’em to sell again.

LADY MACDUFF Thou speak’st with all thy wit,
And yet, i’ faith, with wit enough for thee. 50

SON Was my father a traitor, mother?

LADY MACDUFF Ay, that he was.

SON What is a traitor?

LADY MACDUFF Why, one that swears and lies.

SON And be all traitors that do so? 55

LADY MACDUFF Every one that does so is a traitor
and must be hanged.

SON And must they all be hanged that swear and lie?

LADY MACDUFF Every one.

SON Who must hang them? 60

LADY MACDUFF Why, the honest men.

SON Then the liars and swearers are fools, for there
are liars and swearers enough to beat the honest
men and hang up them.

LADY MACDUFF Now God help thee, poor monkey! But 65
how wilt thou do for a father?

SON If he were dead, you’d weep for him. If you would
not, it were a good sign that I should quickly have a
new father.

LADY MACDUFF Poor prattler, how thou talk’st! 70

Lady Macduff then has a funny bit of banter with her young son about how his father is dead. He doesn't believe her, and they go on to discuss whether or not she should buy a new husband at the market as well as what happens to traitors. The kid is pretty witty. He suggests that there are enough bad men in the world to beat up the good men and hang them, so really, the traitors shouldn't be too concerned about their fates. Then he adds that he knows his dad isn't dead. If he were, Lady Macduff would be crying.

Enter a Messenger.

MESSENGER
Bless you, fair dame. I am not to you known,
Though in your state of honor I am perfect.
I doubt some danger does approach you nearly.
If you will take a homely man’s advice,
Be not found here. Hence with your little ones! 75
To fright you thus methinks I am too savage;
To do worse to you were fell cruelty,
Which is too nigh your person. Heaven preserve
you!
I dare abide no longer. Messenger exits. 80

Lady Macduff is entertained by her son's cheekiness, but the conversation comes to an abrupt end when a messenger enters advising her to flee with her children.

LADY MACDUFF Whither should I fly?
I have done no harm. But I remember now
I am in this earthly world, where to do harm
Is often laudable, to do good sometime
Accounted dangerous folly. Why then, alas, 85
Do I put up that womanly defense
To say I have done no harm?

Enter Murderers.

What are these faces?

Since she's innocent, she sees no reason to leave. Then again, she thinks, this is Earth, where sometimes people are praised for doing evil things and punished for doing good things. So being innocent may not be a good reason to stay put. Unfortunately, in the time it has taken her to figure this out, the murderers have arrived. 

MURDERER Where is your husband?

LADY MACDUFF
I hope in no place so unsanctified 90
Where such as thou mayst find him.

MURDERER He’s a traitor.

SON
Thou liest, thou shag-eared villain!

MURDERER What, you egg?
Stabbing him. Young fry of treachery! 95

SON He has killed
me, mother.
Run away, I pray you.

Lady Macduff exits, crying “Murder!” followed by the
Murderers bearing the Son’s body.

One of the murderers says they're looking for Macduff, who is a traitor. Macduff's son retorts, is stabbed, and then dies, leaving the murderers to pursue mom.

What lie does Lady Macduff tell her son?

Once he is gone, Lady Macduff tells her son that his father is dead, but the little boy perceptively argues that he is not.

What does Macduff's son say?

The boy says, "Then the liars and swearers are fools, for there are liars and swearers enow [enough] to beat the honest men and hang up them" (4.2. 56-58). This joke probably gives Lady Macduff a little smile, because she calls her son a "monkey" and urges him on by asking him again what he will do for a father.

What does Lady Macduff tell her son about Macduff?

She tells her son that his father is dead. Macduff's son tells his mother he will live, “as birds do/…/With what I get, I mean; and so do they” (37-49).

Is Macduff's son brave or foolish?

When they say that Macduff was a traitor, the boy bravely leaps forward and defends his father. Sadly, upon doing this, one of the murderers stabs him. Before he dies however, he tells his mother to run away, who is later caught by them and killed too.