What does this mean: "give me that man/that is not passion's slave."
Give me that man,That is not passion's slave, and I will wear himIn my heart's core, ay, in my heart of heart (3.2)
In many of Shakespeare's plays, the conflict between man's passion and his reason is apparent, especially in Hamlet, who vacillates between action and restraint. In the context of the quote Hamlet appears to be referring to Claudius, who he hopes to catch with a guilty face upon seeing the play that Hamlet has orchestrated.
In this scene, he wanted Horatio to keep a lookout for his uncle, Claudius as he had heard from an apparition, some sort of ghost, that Claudius have indeed murdered his late father so that they can compare their impressions of Claudius's behavior better through observing his movement and his actions. He wanted Horatio to see if Claudius is the real murderer of his late Father. It can prove a more reliable basis for Claudius's guilty conscience other than the unsupported claims by the ghosts which he never met before and he would have no idea or not to believe the spiritual world. Thus, he decided to take the responsibility to explore Claudius's psychotic behavior to see if there is any guilt written in his face that may reveal his darker nature and his horrible deed that he had done
Hamlet wants Horatio to judge the reaction of his uncle to the play he has devised to reveal the suspected murder of his father at the hands of his mother and his uncle. He is appealing to Horatio's reason with the words "not passion's slave." Hamle's own "passon" around the issue clouds his own judgment.