"What a piece of work is a man! how noble in reason!
how infinite in faculty! in form and moving how
express and admirable! in action how like an angel!
in apprehension how like a god! the beauty of the
world! the paragon of animals!"
He then argues against the rationality of man, which is fine, but he does so in a way that presumes Shakespeare meant these lines to represent his true opinion. I think that's a pretty weak assumption. Against his own logic, Hamlet then admits:
"And yet, to me,
what is this quintessence of dust? man delights not
me: no, nor woman neither"
Of course, Hamlet speaks these lines to Rosencrantz and Guildernstern, who have been summoned to spy on Hamlet to deduce the source of his erratic behavior. Later, Ophelia goes "mad" as well. The entire play is about how emotion trumps - or anyway drives - reason! Shakespeare of all people understood behavioral economics. Think of "A horse, a horse, my kingdom for a horse!" - a perfect example of relativity of value!
Just my thoughts.