That within which passes show
Thou know'st 'tis common: all that lives must die,
Passing through nature to eternity.
Ay, madam, it is common.
If it be,
Why seems it so particular with thee?
Hamlet:Hamlet Act 1, scene 2, 72–86
Seems, madam? nay, it is, I know not "seems."
'Tis not alone my inky cloak, good mother,
Nor customary suits of solemn black,
Nor windy suspiration of forc'd breath,
No, nor the fruitful river in the eye,
Nor the dejected havior of the visage,
Together with all forms, moods, shapes of grief,
That can denote me truly. These indeed seem,
For they are actions that a man might play;
But I have that within which passes show,
These but the trappings and the suits of woe.
The queen is peeved. Like her new husband Claudius, she upbraids her son for still mourning his father and for his conspicuous lack of enthusiasm for her recent marriage [see MORE THAN KIN AND LESS THAN KIND]. She finds Hamlet's mourning garb and heavy sighs a bit "particular"—everybody dies, so what's the big fuss? She insinuates that Hamlet is putting on a show just to get attention.
Hamlet snaps back with his famous repudiation of theatricality. His clothing and his gesture may "seem" to be a show; they are indeed things an actor could fabricate. But he has "that within which passes show," that is, feelings which surpass display. His tears, his sighs, his black clothes, his evident dejection are mere tokens of emotions that could never be fully expressed. But by dismissing the notion that he could act out his true self, Hamlet presents us with a paradox: how then could an audience ever understand him?