The Sane Hamlet
Hamlet contains the classic argument between whether or not Hamlet is mad, or a sane man under difficult circumstances. Hamlet assumes antic-disposition at times to uncover the truth of his father's death. From my perspective I believe that Hamlet's actions and thoughts are a logical response to the situation in which he finds himself.
In the first act, Hamlet appears to be very straightforward in his actions and thoughts. When questioned by Gertrude about his melancholy appearance, Hamlet says, "Seems, madam? Nay it is know not seems" (I, ii, 76). This is to say, "I am what I appear to be." Later he makes a clear statement about his thoughts when he commits himself to revenge. Hamlet says,
"I'll wipe away all trivial fond records, All saws of books, all forms, all pressures past, That youth and observation copied there, And thy commandment all alone shall live Within the book and volume of my brain" (I, iv, 99-103).
With this statement, the play makes a transition. Hamlet gives up the role of a student and mourning son, and commits himself to nothing else but the revenge of his father's death. This shows a man who feels justified in his action, and as an outsider we can sympathize with this view.
There is little confusion and certainly no sign of madness in Hamlet's character. In the Chapel Scene, when Claudius is praying alone for his guilt, Hamlet accidentally sees him. He realizes that this is the perfect opportunity to perform the act of revenge. Seeing the opportunity, Hamlet states;
"Now might I do it pat, now a' is a-praying; And now I'll do it, and so he goes to heaven, And so am I reveng'd. That would be scann'd; A villain kills my father, for that, I, his sole son, do this same villain send To heaven. O, this is hire and salary, not revenge" (III, iii, 73-79).
We can witness this ability to reason showing the way in which Hamlet has a sound mind and is far from the position of being mad.
When Hamlet appears again in Act Two, it seems that he has lost his conviction and shows a puzzling duplicitous nature. He has yet to take up the part assigned to him by the ghost. He spends much of the act walking around, reading and talking with Polonius, Rosencrantz, Guildenstern, and the players. It is not until the very end of the act that he even mentions vengeance. If he had any of the conviction shown earlier, he would be presently working on his vengeance. So instead of playing the part of vengeful son, or dropping the issue entirely, he hangs out in the middle, pretending to be mad. This is shown when he says to Rosencrantz and Guildenstern,
"I have of late-but wherefore I know not-- lost all my mirth, forgone all custom of exercise" (II, ii, 298-299).
Later he tells them that he is just feigning madness when he says,
"I am but mad north-north-west, when the wind is southerly, and I know a hawk from a handsaw" (II, ii, 380-381).