Act 3, Sc. 4: Has Hamlet gone mad; and if so, how does his behavior contrast with scenes where he was playing at madness?

Hamlet. Nay, I know not.

Is it the King?

[He lifts up the arras and discovers Polonius, dead]

Queen. Oh what a rash and bloody deed is this!

Hamlet. A bloody deed. Almost as bad, good mother,

As kill a king and marry with his brother.

Queen. As kill a king?

Hamlet. Ay, lady, it was my word.

Thou wretched, rash, intruding fool, farewell.

I took the for thy better. Take thy fortune:

Thou find'st to be too busy is some danger.

Leave wringing of your hands. Peace, sit you down,

And let me wring your heart; for so I shall

If it be made of penetrable stuff,

If damned custom have not brazed it so,

That it be proof and bulwark against sense.

Queen. What have I done, that thou dar'st wag thy tongue

In noise so rude against me?

Hamlet. Such an act

That blurs the grace and blush of modesty,

Calls virtue hypocrite, takes off the rose

From the fair forehead of an innocent love

And sets a blister there, makes marriage vows

As false as dicers' oaths. O, such a deed

As from the body of contraction plucks

The very soul, and sweet religion makes

A rhapsody of words. Heaven's face does glow

O'er this solidity and compound mass

With trisful visage, as against the doom,

Is thought-sick at the act.