Act 1, Sc. 5, lines 35-71: What theme is suggested by the revelation of the truth behind the king's death?

Ghost: Now, Hamlet, hear.

'Tis given out that, sleeping in my orchard,

A serpent stung me. So the whole ear of Denmark

Is by a forgèd process of my death

Rankly abused. But know, thou noble youth,

The serpent that did sting thy father's life

Now wears his crown.

Hamlet: O, my prophetic soul! My uncle!

Ghost: Ay, that incestuous, that adulterate beast,

With witchcraft of his wit, with traitorous gifts---

O wicked wit and gifts, that have the power

So to seduce!---won to his shameful lust

The will of my most seeming-virtuous queen.

O Hamlet, what a falling off was there!

From me, whose love was of that dignity

That it went hand in hand even with the vow

I made to her in marriage, and to decline

Upon a wretch whose natural gifts were poor

To those of mine.

But virtue, as it never will be moved,

Thou lewdness court it in a shape of heaven,

So, lust, though to a radiant angel linked,

Will sate itself in a celestial bed

And prey on garbage.

But soft, methinks I scent the morning air.

Brief let me be. Sleeping within my orchard,

My custom always of the afternoon,

Upon my secure hour thy uncle stole,

With juice of cursèd hebona in a vial,

And in the porches of my ears did pour

The leprous distilment, whose effect

Holds such an enmity with blood of man

That swift as quicksilver it courses through

The natural gates and alleys of the body,

And with a sudden vigor it doth posset

And curd, like eager droppings into milk,

The thin and wholesome blood.