Histeria!

Aka Pella:
Like, mister, are you okay?

Toast:
I think the dude's having a nervous breakdown.

René Descartes:
Oh, you think so, do you?! Well, I think that -- Think? Think! That's it! "I think, therefore I am!" I did it! I did it, huhuhu! [in singsong] I found a basic axiom upon which to be acknowledged!

Toast:
Spare me the details, brainy-dude. Can I get paid for the pizza now?

René Descartes:
No no no, wait wait, I'm on a role! "I think, therefore I am!" Don't you see? It is so simple! If I think, then I exist. If I don't think, then I don't exist! Now I can solve any mystery known to man! Go ahead, ask me something! Something!

Toast:
Who's gonna pay for this pizza?

René Descartes:
I--I don't know. I have absolutely no idea. I can't think! Therefore I am-- [suddenly vanishes]

Toast:
Gone, chuh! The dude stiffed me!

Loud Kiddington:
What a gyp!!

Toast:
Hey! Don't disappear on me, deadbeat philosopher dude! Think yourself back into existence! Somebody's gotta pay for the pie, man!