Dictionary.com
Thesaurus.com

cogito, ergo sum

American  
[koh-gi-toh er-goh soom, koj-i-toh ur-goh suhm, er-goh] / ˈkoʊ gɪˌtoʊ ˈɛr goʊ ˈsʊm, ˈkɒdʒ ɪˌtoʊ ˈɜr goʊ ˈsʌm, ˈɛr goʊ /
Latin.
  1. I think, therefore I am (stated by Descartes as the first principle in resolving universal doubt).


cogito, ergo sum British  
/ ˈkɒɡɪˌtəʊ ˈɜːɡəʊ ˈsʊm /
  1. I think, therefore I am; the basis of Descartes' philosophy

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

René Descartes summed this up in his famous phrase: cogito ergo sum – I think, therefore I am.

From The Guardian • Jan. 6, 2018

This is the idea behind Descartes’ bumper-sticker statement, cogito ergo sum.

From Slate • Jun. 7, 2013

They begin with cogito ergo sum, and they rely not on seduction but sophistry, not on rolled-down beds but revved-up minds, not on fervid matings but frenetic misunderstandings.

From Time Magazine Archive

By the existential act of rejecting cogito, ergo sum for sum, ergo sum, they have taken on, willy-nilly, a vast commitment toward a kindlier, more equitable society.

From Time Magazine Archive

The next year Descartes formulated his famous doctrine cogito ergo sum, ‘I think therefore I am’; consequently, there is something, one thing, I know for certain.

From "The Invention of Science" by David Wootton