Claudius' murdering of his brother, the king is the first murderous act of mental illness in the story and it sets into course the madness of many other characters. Murdering one's brother so that they may marry their sister in law is not the act or desire of a sane person. After the king's death, Claudius and Gertrude marry within a matter of months. This quick marriage circumvents the standard mourning period of one year that is expected of a queen. Hamlet is greatly disturbed by the fact that his mother does not mourn longer for his fathers death and conveys his anger about this subject on several occasions. The marriage of a man to his sister in law is thought incestuous by the church and contributes to the overall lack of decency in this story. Claudius is directly responsible for the death of the king, Hamlet's father, and he also contributes to the deaths of Gertrude and Hamlet. His actions set into course a series of events of which the end result is the deaths of Polonius, Laertes, and Ophelia. He is also indirectly responsible for the deaths of these characters.
's 1957 essay "The Character of Hamlet's Mother" defends Gertrude, arguing that the text never hints that Gertrude knew of Claudius poisoning King Hamlet. This analysis has been praised by many feminist critics, combating what is, by Heilbrun's argument, centuries' worth of misinterpretation. By this account, Gertrude's worst crime is of pragmatically marrying her brother-in-law in order to avoid a power vacuum. This is borne out by the fact that King Hamlet's ghost tells Hamlet to leave Gertrude out of Hamlet's revenge, to leave her to heaven, an arbitrary mercy to grant to a conspirator to murder. This view has not been without objection from some critics.
Hamlet the prince is a mortal god in an immortal play.”
There need he no doubt, then, that Hamlet's madness was really feigned. He saw much to be gained by it, and to this end he did many things that the persons of the drama must construe as madness. His avowed intention was to throw them off the track. To understand the madness as real is to make of the play a mad-house tragedy that could have no meaning for the very sane Englishmen for whom Shakespeare wrote. There is dramatic value in such madness as Lear's, for the play traces the causes of his madness, and the influences that restore him. Lear's madness had its roots in his moral and spiritual defects, and the cure was his moral regeneration. But no such dramatic value can be assigned to Hamlet's madness. Shakespeare never makes of his dramas mere exhibitions of human experience, wise or otherwise, but they are all studies in the spiritual life of man. His dramas are always elaborate attempts to get a meaning out of life, not attempts to show either its mystery, or its inconsequence, or its madness. If Hamlet were thought of as truly mad, then his entrances and his exits could convey no meaning to sane persons, except the lesson to avoid insanity. But it needs no drama to teach that.