I guess it depends on how we define "think". That's the word we tend to use because Descartes used the French/Latin equivalent, but a better word might be "experiencing".
"I experience, therefore I am."
The specific details of the experience may be fictional (or illusory), but the act of experiencing in itself cannot be an illusion.
As I gather, Latin has some complex and pedantic syntax, but it is not a semantically precise language. A word can have a range of different meanings, and it's not always completely clear in latin text, which of those meanings is the intended one. "cogito" for example may imply various cognitive processes.
"I experience, therefore I am."
The specific details of the experience may be fictional (or illusory), but the act of experiencing in itself cannot be an illusion.
As I gather, Latin has some complex and pedantic syntax, but it is not a semantically precise language. A word can have a range of different meanings, and it's not always completely clear in latin text, which of those meanings is the intended one. "cogito" for example may imply various cognitive processes.