The Evil Genius of René Descartes

Here I briefly explain why Descartes introduces the Evil Genius argument in the Meditations.

[Ivytheherbert]

I thought this was going to be about the ways Descartes was evil, like how he tried to prove animals aren't sentient because they "automatically" respond with terror when he did things like throw them out of a window.

[andymontes]

Would it not make knowledge impossible and therefore he could not know he was being deceived? Is it not a self-refuting world view?

[brimstone]

If a puppet acts because of strings, does the puppet exist? Or are they merely the puppeteer?
If all are senses are illusions, and even our mind not our own, does that not mean we are indeed the person controlling ourself?