LATIN DICTIONARYLexicon Latīnum

Cōgitō, ergō sum

“I think, therefore I am”

COGITO · ERGO · SVM

Later Latin: medieval or modern

Descartes, Principles of Philosophy 1.7 (1644)

The first certainty of Descartes's philosophy.

Word by word

  1. Cōgitōcōgō -eredrive together; compel2nd sg. fut. act. imper.
  2. ergōergōtherefore
  3. sumsum essebe, exist; fut. infin. often = fore, impf. subj. often = forem for essem1st sg. pres. act. ind.

Using it as a motto or tattoo

Latin endings carry gender and number, so a saying about one person may need changing for another. Check your own version, or have three new ones composed, on the motto desk.

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Quick answers

What does “Cogito, ergo sum” mean?
“Cōgitō, ergō sum” means “I think, therefore I am”. The first certainty of Descartes's philosophy.
Who said “Cogito, ergo sum”?
It is not classical: Descartes, Principles of Philosophy 1.7 (1644).

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