revenge his foul murder. And the ghost lamented to his son, that his
mother should so fall off from virtue, as to prove false to the wedded
love of her first husband, and to marry his murderer: but he cautioned
Hamlet, howsoever he proceeded in his revenge against his wicked
uncle, by no means to act any violence against the person of his
mother, but to leave her to heaven, and to the stings and thorns of
conscience. And Hamlet promised to observe the ghost's direction in
all things, and the ghost vanished.

And when Hamlet was left alone, he took up a solemn resolution, that
all he had in his memory, all that he had ever learned by books or
observation, should be instantly forgotten by him, and nothing live in
his brain but the memory of what the ghost had told him, and enjoined
him to do. And Hamlet related the particulars of the conversation
which had passed to none but his dear friend Horatio; and he enjoined
both to him and Marcellus the strictest secrecy as to what they had
seen that night.

The terror which the sight of the ghost had left upon the senses of
Hamlet, he being weak and dispirited before, almost unhinged his
mind, and drove him beside his reason. And he, fearing that it would
continue to have this effect, which might subject him to observation,
and set his uncle upon his guard, if he suspected that he was
meditating any thing against him, or that Hamlet really knew more of
his father's death than he professed, took up a strange resolution
from that time to counterfeit as if he were really and truly mad;
thinking that he would be less an object of suspicion when his uncle
should believe him incapable of any serious project, and that his real
perturbation of mind would be best covered and pass concealed under a
disguise of pretended lunacy.