Hamlet is an emotional human being who feels guilt, remorse, and has responsibilities; he also feels pride and a sense of duty. Hamlet's indecisiveness in killing Claudius is justified through the nature, actions, and beliefs of many characters.
The Ghost, Hamlet's father, explained his death and instructed Hamlet to kill Claudius. Hamlet describes the Ghost as, "My father's spirit in arms! All is not well" (1.2). Hamlet says in act one, scene five, "Haste me to know't, that I, with wings as swift as meditation or the thoughts of love, may sweep to my revenge" (1.5). Hamlet feels passionate about his role until he has time to recollect. Upon recollection Hamlet considers that this may be an evil ghost so he delays killing Claudius. He considers the Ghost may be a, "spirit of health or goblin damned" (1.5). He is intelligent in this decision because if it were not a holy ghost he could be damned for killing Claudius.
The Prince, Hamlet, has several opportunities to kill Claudius which he fails to capitalize on. One of the opportunities is while Claudius is praying at church. Hamlet is astute and decides against killing the King, because he is purged of his sins. The Prince is unsure of Claudius" guilt up to the point of the play, "The Murder of Gonzago" (2.2). Preventing the king from going to Heaven and the need to confirm the King's guilt are two valid reasons Hamlet delays killing the King. .
Hamlet has many internal conflicts which also prevent him from killing the King. He becomes obsessed with proving he has an antic disposition which draws focus away from his goal of killing the King; Hamlet becomes obsessed with proving he has an antic disposition. This draws focus away from his goal of killing the King. Hamlet also becomes enraged at his mother for marrying his uncle. Both proving Hamlet has an antic disposition and his obsession with his mother only add to the validity of Hamlet's actions.