“A guy walks into a bar…” is a typical form of what has been called the “bar joke.” A popular philosophy variation is:
 
“René Descartes walks into a bar, see. He orders a glass of wine and drinks it. The bartender says, ‘Would you like another?’ Descartes replies, ‘I think not.’ And he disappears.”
 
French philosopher René Descartes (1596-1650) is famous for the line, “Cogito ergo sum” (French: Je pense, donc je suis; English: I think, therefore I am). The joke has been cited in print since at least 1990.
 
A related bar joke includes the pun “Descartes before the horse.”
 
         
Wikipedia: René Descarte
René Descartes (/ˈdeɪˌkɑːrt/; French: [ʁəne dekaʁt]; Latinized: Renatus Cartesius; adjectival form: “Cartesian”; 31 March 1596 – 11 February 1650) was a French philosopher, mathematician, and scientist. Dubbed the father of modern western philosophy, much of subsequent Western philosophy is a response to his writings, which are studied closely to this day. He spent about 20 years of his life in the Dutch Republic.
(...)
His best known philosophical statement is “Cogito ergo sum” (French: Je pense, donc je suis; I think, therefore I am), found in part IV of Discourse on the Method (1637; written in French but with inclusion of “Cogito ergo sum”) and §7 of part I of Principles of Philosophy (1644; written in Latin).
         
29 June 1990, The Orange County Register (Santa Ana, CA), “They don’t have to be very funny; they’re smart” by Dan Froomkin, pg. B1, col. 2:
Rene Descartes walks into a bar, see. He orders a glass of wine and drinks it. The bartender says, “Would you like another?” Descartes replies, “I think not.” And he disappears.
 
That was a Mensa joke.
 
Google Books
Louisiana Power & Light
By John Dufresne
New York, NY: Plume
1994
Pg. 216:
“Rene Descartes walks into a bar, hops up on a stool, doesn’t say anything. The bartender recognizes him, figures, a philosopher, classy guy, probably drinks the best. So he goes up to Descartes, wipes the bar in front of him, and says, ‘Can I get you a drink, M. Descartes? Chartreuse? B&B? A cognac. perhaps?’ Descartes looks at the bartender, says, ‘I think not,’ and disappears.”
 
And yes, the joke did seem to settle some nerves and did set off a flurry of variations on Descartes’ most famous theme, lines like, “I think, therefore I think I can, I think I can,” (The Little Engine That Could); “I think, therefore I’m Kant”; ...
 
Google Books
Surrender, Dorothy:
A Novel
By Meg Wolitzer
New York, NY: Scribner
1999
Pg. 59:
“Descartes walks into a bar, and the bartender asks him, ‘Would you like a drink?’ And Descartes says, ‘I think not,’ and then he disappears.”
   
Google Books
Man Walks into a Bar:
Over 6,000 of the Most Hilarious Jokes, Funniest Insults and Gut-Busting One-Liners
By Stephen Arnott and Mike Haskins
Berkeley, CA: Ulysses Press
2007
Pg. 116:
Descartes walks into a bar. The bartender asks, “Can I get you a drink?” Descartes replies, “I think not”...and disappears.
 
Twitter
lacehu
‏@lacehu
Descartes walks into a bar. The bartender asks, “Would you like a beer?” Descartes replies, “I think not”, then disappeared.
6:41 AM - 4 Dec 2007
 
Salon
MONDAY, JUL 1, 2013 07:15 PM EDT
The 10 nerdiest jokes of all time
Courtesy of a Reddit thread, these will make you the toast of your next philosophy study group
THERESA FISHER
(...)
“Rene Descartes walks into a bar and proceeds to order many drink[s]. The bartender says to him a while later, seeing he is completely inebriated, ‘I think you’ve had enough.’ Descartes slurs, ‘I think not!’ Then he disappears.”
 
Obviously, fallacy fan girls and boys might scowl and accuse the joke of denying the antecedent. (Refresher: Descartes said, “I think therefore I am.” So, according to the rules of formal logic, thinking implies existence, but not thinking doesn’t imply nonexistence.) Be careful! Logicians can be super-douchey.
 
Twitter
Dr. E. Droge
‏@Tips2bSmarter
Descartes walks into a bar
Bartender:“Whiskey?”
Descartes:“I think not”
Descartes vanishes
#CEO #college #JFK #LGA #ORD #school #London #IQ
11:18 AM - 20 Feb 2016