“I drink, therefore I am” (Bibo ergo sum) is a jocular saying that has been printed on many gift items, such as T-shirts and bumper stickers. The saying is a parody of the philosophical proposition by René Descartes (1596-1650), “I think, therefore I am” (Cogito ergo sum).
 
“I drink, therefore I am” has been cited in print since at least 1925. “Bibo ergo sum” has been cited in print since at least 1886.
 
   
Wikipedia: Cogito ergo sum
Cogito ergo sum (/ˈkoʊɡɨtoʊ ˈɜrɡoʊ ˈsʊm/, also /ˈkɒɡɨtoʊ/, /ˈsʌm/; Classical Latin: [ˈkoːɡitoː ˈɛrɡoː ˈsʊm], “I think, therefore I am”) is a philosophical proposition by René Descartes. The simple meaning of the Latin phrase is that thinking about one’s existence proves—in and of itself—that an “I” exists to do the thinking; or, as Descartes explains, “[W]e cannot doubt of our existence while we doubt … .”
 
This proposition became a fundamental element of Western philosophy, as it was perceived to form a foundation for all knowledge. While other knowledge could be a figment of imagination, deception or mistake, the very act of doubting one’s own existence arguably serves as proof of the reality of one’s own existence, or at least of one’s thought.
   
Descartes’ original phrase, ej pense, donc je suis (French pronunciation: ​[ʒə pɑ̃s dɔ̃k ʒə sɥi]), appeared in his Discourse on the Method (1637), which was written in French rather than Latin to reach a wider audience in his country than scholars. He used the Latin cogito ergo sum in the later Principles of Philosophy (1644).
 
Wikipedia: List of Latin phrases
bibo ergo sum 
I drink, therefore I am  
A play on “cogito ergo sum”, “I think therefore I am”
   
HathiTrust Digital Library
The Cornellian
Ithaca, NY: Cornell University
1886
Pg. 139:
Our dictum, for a philosophy without a dictum is not worth much, is—Bibo Ergo Sum. It will be urged, no doubt, that this is an adaptation from Descartes. We frankly admit that it is, but we maintain that while “Cogilo Ergo Sum” is good, Bibo Ergo Sum is infinitely better.
 
15 September 1907, New Orleans (LA) Item, “The Most Wonderful Thing in the World,” pg. 5, col. 7:
The baby at the top of this page, turning to his first meal on this earth, might say with just as much and as solemn meaning, “I DRINK, therefore I am.”
 
7 November 1925, Hamilton (OH) Evening Journal, “The Fire of Thought.” Editorial, Pictorial and Magazine Section, pg. 1, col. 1:
Many of us in these prohibition days might well say, “I DRINK, therefore I am.” Or better still, “I DRINK, therefore I am NOT.”
 
Google Books
The Booze Reader;
A soggy sSga of Man in His Cups
By George Victor Bishop
Los Angeles, CA: Sherbourne Press
1965
Pg. 53:
In the absence of the founding of a philosophical school whose dictum might reasonably be expressed in the phrase “I Drink — Therefore I Am,” people have always found it necessary to drink because of something.
 
Google Books
Winter Blood
By John Roc
New York, NY: Trident Press
1971
Pg. 223:
He held up his glass. “Bibo, ergo sum.”
   
Google Books
The Comic Encyclopedia:
A Library of the Literature and History of Humor Containing Thousands of Gags, Sayings, and Stories
By Evan Esar
Garden City, NY: Doubleday
1978
Pg. 125:
drunkard: I drink, therefore I am.
 
Twitter
Jonathan Green
‏@GreenJ
Bibo ergo sum.
3:37 PM - 13 Feb 2009
 
Urban Dictionary
bibo ergo sum
Latin phrase for “I drink therefore I am”
-“Let’s go party tonight!”
-“Bibo ergo sum!”
-“Whaaat?!”
-“I drink therefore I am!”
-“Yeaaah!”
by jakeUCLA August 18, 2009
   
Twitter
Defining New Media
‏@DefineNewMedia
Bibo, ergo sum. - I drink, therefore I am - Fredirect Toyou
12:33 AM - 26 May 2014