in 2.2 482-520 hamlet rebukes himself for not acting. why has he not acted? because he is a coward (line 503)? because he has a conscience?
The play is a dramatization of the difficulties of any action – of making the decision to act or not act. Hamlet has no “proof” of his uncle’s guilt – only a “ghost” which may be an evil temptation and not really his father’s spirit. He does not want to act if the ghost is nothing but his own distorted desire for power.