I was reading about what Descartes said, this famous sentence:
Cogito, ergo sum. I think, therefore I am.
Which everybody knows and learns in school. But if you look
at that sentence - really it says: Dubito, ergo cogito, ergo sum.
I doubt, therefore I think, therefore I am.
Isn't that surprising? I didn't know it either, because I never
looked it up.
You see cogito ergo sum on T-shirts all over the world -
but dubito has a bad press. That's very provocative.
Everything starts in doubt. Or it also could mean hesitation,
but same idea.

Anne Carson