Why "Cartesian"?

The adjective for anything pertaining to Desacrtes is “Cartesian.” Why isn’t it “Descatesian”? (This has gotta be one of the shortest GQ questions ever).

Descartes’ last name in Latin, isn’t Descartes. It’s Cartesianus.

The Latin form of Descartes is Renatius Cartesius. Latinization of names was once the practice, as Latin was the international language of scholars and learned people.

I should have known Latin had something to do with it. Every time I come up with a language question, the answer invariably turns out to be “Latin”, the most alive “dead” language in the history of the world. Thanks, guys.

But hey, which was it: Cartesianus or Cartesius? I’m gonna be lying awake worrying now.

Latin: The Zombie Language!

The Columbia Encyclopedia has it as “Cartesius” as well as the Britannica.

Upon further review, my dictionary says “Cartesianus” is a Latin adjective.

Could have just called it “Reneian” and been done with it.