Rene Descartes walks into a bar. The Bartender says, ""Hey, Rene, you want a scotch?"" Descartes replies, ""No, I think not."" And then he vanishes. No dice.

Rene Descartes walks into a bar The bartender says would you like a beer? Descartes says ""I think not"" and promptly vanishes.

Rene Descartes walks into a bar. The bartender says, ""Would you like a beer?"" Descartes says ""I think not"" and he drops dead.

Rene Descartes is having dinner alone at a restaurant... ...when he finishes his meal, the waiter approaches and says ""and will monsieur be having dessert?"" ""I think not"" Descartes replies. Poof! He disappears.