Hamlet's Soliloquy: O, what a rogue and peasant slave am I! (2.2)
In addition to revealing Hamlet's plot to catch the king in his guilt, Hamlet's second soliloquy uncovers the very essence of Hamlet's true conflict. For he is undeniably committed to seeking revenge for his father, yet he cannot act on behalf of his father due to his revulsion toward extracting that cold and calculating revenge. "Hamlet's sense of himself as a coward is derived from a crude, simplistic judgment turning on whether or not he has yet taken any action against the man who murdered his father. His self-condemnation takes several bizarre forms, including histrionic imaginings of a series of demeaning insults that he absorbs like a coward because he feels he has done nothing to take revenge on Claudius" (Newell 61).
Determined to convince himself to carry out the premeditated murder of his uncle, Hamlet works himself into a frenzy (the culmination of which occurs at lines 357-8). He hopes that his passions will halt his better judgement and he will then be able to charge forth and kill Claudius without hesitation. But Hamlet again fails to quell his apprehensions of committing murder and cannot act immediately. So he next tries to focus his attention on a plan to ensure Claudius admits his own guilt. He returns to an idea that had crossed his mind earlier -- that of staging the play The Mousetrap. Hamlet is convinced that, as Claudius watches a re-enactment of his crime, he will surely reveal his own guilt. Hamlet cannot take the word of his father's ghost, who really might be "the devil" (573), tricking him into damning himself. Thus, he must have more material proof before he takes Claudius's life -- he must "catch the conscience of the king."