Shakespeare's Hamlet is a drama in which appearance is contradictory to reality, actions contradictory to words, conduct contradictory to purpose. There is great deception and nothing endures--certainly no passionate moment. Multiple acts of spying contribute to these existential contradictions.
- Act II, Scene 1
Having returned to Denmark for the funeral of King Hamlet, Laertes has requested of the new king, Claudius, to be allowed to return to France where he has been studying. After he has gone, Polonius summons his man Reynaldo and provides him money for Laertes. He then orders him to go to France and spy on Laertes. He tells Reynaldo to first ask around about Laertes's behavior and then visit him. Then, Reynaldo should get closer to those around Laertes and pretend to think that Laertes is wild and wanton in order to draw a candid reaction from his associates.
....And there put on him
What forgeries you please; marry, none so rank
As may dishonour him. Take heed of that.
But, sir such wanton, wild, and usual slip
As are companions noted and most known
To youth and liberty. (2.1.19-24)
Polonius rationalizes that because many young men given "liberty" are prone to act injudiciously, he needs to be aware of his son's behavior.
- Act II, Scene 2
Polonius informs King Claudius and Queen Gertrude, of Hamlet's behavior and "[T]he head and source of all your son's distemper" (2.2.55). Polonius declares "Your noble son is mad" and the cause of his madness is his love for Ophelia, Polonius's daughter. After showing the king and queen letters that Hamlet has written to Ophelia, Polonius then proposes a plan to prove the madness of Hamlet. When Hamlet takes his customary walks in the lobby of the castle, they hide themselves behind as arras as Polonius has his daughter confront Hamlet.
Be you and I behind an arras then.
Mark the encounter. If he love her not,
And be not from his reason fall'n thereon,
Let me be no assistant for a state,
But keep a farm and carters. (2.2.162-166)
Later in this same scene, Hamlet encounters his boyhood friends Rosencrantz and Guildenstern, but he is mistrustful of them, knowing that they have been summoned to Denmark. When Hamlet asks them the purpose of their "visitation," Guildenstern asks, "What should we say, my lord?" Hamlet insinuates that they are spying on him,
Anything but to th'purpose. You were sent for, and there is a kind of confession in your looks, which your modesties have not craft enough to cover. I know the good king and queen have sent for you. (2.2.266-269)
Further, when the troupe of actors arrive at the castle, Hamlet designs a plan to entrap Claudius by having a play performed, the plot of which follows closely what he suspects his uncle has done as told to him by the ghost of his father. If Claudius reacts, then Hamlet can also act.
The play's the thing
Wherein I'll catch the conscience of the king. (2.2.561-562)
- Act III, Scene 1
Kind Claudius questions Rosencrantz and Guildenstern about their meeting with Hamlet, asking if by some deception they procured any information on Hamlet's behavior:
And can you by no drift of conference
Get from him why he puts on this confusion (3.1.1-2)
After Rosencrantz and Guildenstern depart, Claudius asks Gertrude to leave as well. He has sent for Hamlet and designed that on his way he will encounter Ophelia, who will be instructed to walk around the lobby. He and Polonius will then hide and eavesdrop on Hamlet's conversation with Ophelia.
Her father and myself (lawful espials)
We'll so bestow ourselves that, seeing unseen,
We may of their encounter frankly judge,
And gather by him, as he is behaved,
If't be th'affliction of his love or no
That thus he suffers for. (3.1.32-37)
Claudius thus justifies his spying as his earnest desire to know what ails Hamlet so that help can be given Hamlet. In truth, he is worried about what Hamlet may know about his father's death.