“Come let me clutch thee:—
I have thee not and yet I see thee still.
Art thou not, fatal vision, sensible
To feeling as to sight? or art thou but
A dagger of the mind, a false creation
Proceeding from the heat-oppressed brain?
I see thee yet in form as palpable
As that which now I draw....
- - - - - - - -
Mine eyes are made the fools o' the other senses.
Or else worth all the rest: I see thee still;
And on thy blade and dudgeon gouts of blood
Which was not so before.—There's no such thing.”
What is all this but an illustration of Hamlet's assertion:
“There is nothing either good or bad
But thinking makes it so.”
Just too as Hamlet swings on his mental balance, so that it is still a debated question among academic critics whether his madness was feigned or real, so here Shakespeare shows us how Macbeth loses his foothold on reality and falls into the void.
The lyrical effusion that follows is not very successful, and probably on that account Macbeth breaks off abruptly:
“Whiles I threat he lives,
Words to the heat of deeds too cold breath gives,”
which is, of course, precisely Hamlet's complaint:
“This is most brave;
That I, the son of a dear father murdered,
Prompted to my revenge by heaven and hell,
Must, like a whore, unpack my heart with words.”
After this Lady Macbeth enters, and the murder is committed, and now wrought to the highest tension Macbeth must speak from the depths of his nature with perfect sincerity. Will he exult, as the ambitious man would, at having taken successfully the longest step towards his goal? Or will he, like a prudent man, do his utmost to hide the traces of his crime, and hatch plans to cast suspicion on others? It is Lady Macbeth who plays this part; she tells Macbeth to “get some water,”
“And wash this filthy witness from your hand,”