-Let me put it this way: have you ever heard of Plato, Aristotle, Socrates?
-Yes.
-Morons.
-Really! In that case, I challenge you to a battle of wits.
-For the princess? To the death? I accept!
-Good, then pour the wine...Inhale this, but do not touch.
-I smell nothing
-What you do not smell is iocane powder. It is odorless, tasteless, dissolves instantly in liquid and is among the most deadly poisons known to man.
-Hmm
-All riight: where is the poison? The battle of wits has begun. It ends when you decide and we both drink and who is right and who is dead.
-But it's so simple. All I have to do is divine it from what I know of you: are you the sort of man who would put the poison into his own cup or his enemies. Now, a clever man would put the poison into his own goblet because he would know that only a great fool would reach or what he is given. I am not a great fool, so I can clearly not choose the wine in front of you. But you must have known that I am not a great fool, so I can clearly not choose the wine in front of me.
-You've made your decision then?
-Not remotely! Because Iocane comes from Australia. As everyone knows, Australia is entirely peopled with criminals. And criminals are used to having people not trust them as you are not trusted by me. So I can clearly not choose the wine in front of you.
-Truly, you have a dizzying intellect.
-Wait 'til I get going! Where was I?
-Australia.
-And you must have suspected that I would have known the poison's origin, so I can clearly not choose the wine in front of me!
-You're just stalling now.
-You'd like to think that, wouldn't you? You've beaten my giant, which means that you're exceptionally strong...so you could have put the poison in your own cup, depending on your strength to save you, so clearly I cannot choose the wine in front of you. But you've also bested my Spaniard, which means you must have studied and in studying you must have learned that man is mortal, so you wouldhave put the poison as far from yourself as possible, so I can clearly not choose the wine in front of me.
-You're trying to trick me into giving away something. It won't work.
-It has worked! You've given everything away! I know where the poison is!
-The make your choice.
-I will and I choose...What in the world can that be?

Part of it:

Vizzini: Now, a clever man would put the poison into his own goblet, because he would know that only a great fool would reach for what he was given. I am not a great fool, so I can clearly not choose the wine in front of you. But you must have known I was not a great fool, you would have counted on it, so I can clearly not choose the wine in front of me.
Vizzini: You only think I guessed wrong - that's what's so funny. I switched glasses when your back was turned. Ha-ha, you fool. You fell victim to one of the classic blunders, the most famous of which is "Never get involved in a land war in Asia", but only slightly less well known is this: "Never go in against a Sicilian, when *death* is on the line.". Hahahahahah.