I think; therefore I am

Cultural

A statement by the seventeenth-century French philosopher René Descartes. “I think; therefore I am” was the end of the search Descartes conducted for a statement that could not be doubted. He found that he could not doubt that he himself existed, as he was the one doing the doubting in the first place. In Latin (the language in which Descartes wrote), the phrase is “Cogito, ergo sum.”

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.

I think, therefore I am a polar bear.

From Literature

In the 17th century, René Descartes connected the idea of the self to consciousness when he famously stated, “I think, therefore I am.”

From Salon

Let’s give the last word, plus one of mine, to the famous phrase of French philosopher and scientist Rene Descartes: “Cogito ergo sum ridens” — “I think, therefore I am laughing.”

From Los Angeles Times

An early effort came in the 17th century, by the French philosopher René Descartes who said: "I think therefore I am."

From BBC

Literature and philosophy love pithy phrases such as “I think, therefore I am” from Frenchman René Descartes.

From Washington Post

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023