Edgar, in monologue, decides his maligned state is better than hypocritical flattery, and that hope always follows despair. He then espies his father led by an old man, and is suitably shocked by what he sees: “World, world, O world.” Gloucester has sunk into complete despair: “I have no way, and therefore want no eyes.” Edgar sees that what he thought was the worst has worsened still. Gloucester hints that his meeting of mad Tom the night before brought his son to mind, a sad thought: “As flies to wanton boys are we to the gods—they kill us for the sport.” The old man identifies mad Tom, and Gloucester suggests that such a person is a perfect fit to lead him on. Edgar of course agrees, but he maintains his “mad Tom” speech. In a gesture to biblical redistribution to the poor, Gloucester gives Edgar his purse to give away, “and each man have enough.” He then asks Edgar to lead him to Dover and its cliffs, hinting that his purpose is to throw himself from their heights.
ACT IV. SCENE I. The heath.
Yet better thus, and known to be contemned
Than still contemned and flattered. To be worst,
The lowest and most dejected thing of fortune,
Stands still in esperance, lives not in fear.
The lamentable change is from the best, 
The worst returns to laughter. Welcome, then,
Thou unsubstantial air that I embrace.
The wretch that thou hast blown unto the worst
Owes nothing to thy blasts. But who comes here?
Enter Gloucester, and an Old Man
My father, poorly led? World, world, O world! 
But that thy strange mutations make us hate thee,
Life would not yield to age.
Old Man [to Gloucester]
O, my good lord, I have been your tenant and
your father’s tenant these fourscore years.
Away, get thee away, good friend, begone. 
Thy comforts can do me no good at all.
Thee they may hurt.
Old Man You cannot see your way.
I have no way, and therefore want no eyes.
I stumbled when I saw. Full oft ’tis seen 
Our means secure us and our mere defects
Prove our commodities. O dear son Edgar,
The food of thy abused father’s wrath,
Might I but live to see thee in my touch,
I’d say I had eyes again. 
Old Man How now, who’s there?
O gods! Who is’t can say ‘I am at the worst’?
I am worse than e’er I was.
Old Man ‘Tis poor mad Tom.
And worse I may be yet. The worst is not 
So long as we can say ‘This is the worst.’
Old Man Fellow, where goest?
GLOUCESTER Is it a beggarman?
Old Man Madman and beggar too.
He has some reason, else he could not beg. 
I’th’ last night’s storm I such a fellow saw,
Which made me think a man a worm. My son
Came then into my mind, and yet my mind
Was then scarce friends with him. I have heard more since.
As flies to wanton boys, are we to th’ gods. 
They kill us for their sport.
EDGAR [Aside] How should this be?
Bad is the trade that must play fool to sorrow,
Angering itself and others. [to Gloucester] Bless thee, master!
GLOUCESTER Is that the naked fellow? 
Old Man Ay, my lord.
Then prithee get thee away. If for my sake
Thou wilt o’ertake us, hence a mile or twain,
I’th’ way toward Dover, do it for ancient love,
And bring some covering for this naked soul, 
Who I’ll entreat to lead me.
Old Man Alack, sir, he is mad.
‘Tis the times’ plague when madmen lead the blind.
Do as I bid thee, or rather do thy pleasure.
Above the rest, begone. 
I’ll bring him the best ‘pparel that I have,
Come on’t what will. Exit
GLOUCESTER Sirrah, naked fellow.
EDGAR Poor Tom’s a-cold. [Aside] I cannot daub it further.
GLOUCESTER Come hither, fellow. 
EDGAR [Aside] And yet I must. [to Gloucester]
Bless thy sweet eyes, they bleed.
GLOUCESTER Know’st thou the way to Dover?
Both stile and gate, horseway and footpath. Poor
Tom hath been scared out of his good wits. Bless 
thee, goodman’s son, from the foul fiend. [Five
fiends have been in Poor Tom at once—of lust, as
Obidicut; Hobbididence, prince of dumbness; Mahu, of
stealing; Modo, of murder; Flibbertigibbet, of
mopping and mowing, who since possesses chambermaids 
and waiting-women. So, bless thee, master!]
Here, take this purse, thou whom the heavens’ plagues
Have humbled to all strokes. That I am wretched
Makes thee the happier. Heavens deal so still.
Let the superfluous and lust-dieted man 
That slaves your ordinance, that will not see
Because he doth not feel, feel your power quickly,
So distribution should undo excess,
And each man have enough. Dost thou know Dover?
EDGAR Ay, master. 
There is a cliff whose high and bending head
Looks fearfully in the confined deep.
Bring me but to the very brim of it
And I’ll repair the misery thou dost bear
With something rich about me. From that place 
I shall no leading need.
EDGAR Give me thy arm. Poor Tom shall lead thee.
[In McKellen film, these lines taken from above: “five fiends
have been in poor Tom at once; as Obidicut; Hobbididence,
Mahu, of Modo.”]