This has always been an over-exaggerated trait of Hamlet. He is not indecisive—he simply needs real “ocular” proof of his father’s murder, not just “visions”, which could be the manipulations of the devil. As soon as he sees his uncle’s reaction to the players’ “Mousetrap” play, he is ready to act. He has good reason not to kill Claudius while he is praying; it is not indecision that makes him wait. The play is, among other things, a dramatization of the human dilemma in Justice to separate personal emotions from true retribution for crimes, to use reason and logic—what is called “ocular proof”—not mere emotional reaction. It is a lesson we could all learn from this masterpiece. Seeing the action as “inability to decide” strips the complex character of Hamlet down to a sophomoric stereotype, while Shakespeare was constructing a character embodying high moral maturity and ethical responsibility.
Hamlet's indecisiveness and procrastination have puzzled readers for some four hundred years, and nobody has been able to come up with a conclusive explanation for what may be his "tragic flaw." Samuel Taylor Coleridge, a brilliant man who may have suffered from the same tragic flaw, opined that Hamlet thinks too much. This may be because he is too intelligent and too learned. Consider how many different languages he knows. He knows Danish, of course. He must know Latin in order to be able to get into Wittenberg, and he probably knows some ancient Greek. He undoubtedly knows French because that was the language of culture. We can assume that he is fluent in English, not only because he is speaking English in the play (although we are supposed to assume that is really Danish), but because he is being sent to England as an ambassador. He must be fluent in German if he is going to a German university. During the play-within-a-play he comments that "The story is extant and written in very choice Italian," a remark which only seems intended to show that Hamlet is a connoisseur of the Italian language. No doubt Hamlet is also acquainted with Swedish and Norwegian. He seems like a scholar who is suddenly called upon to be a man of action and is unprepared for the radical transition. He is an introvert, a loner, a reader, an intellectual. He wants to understand things before he acts, and he never gets to the point where he fully understands the situation, just as we readers never fully understand the play itself. Although Hamlet is thirty years old and must have been attending classes at Wittenberg for many years, he wants to go back to Wittenberg and study some more; but he is prevented from doing so by his wily stepfather the king, who wants to keep him a virtual prisoner and keep his eye on him.