Whatever is, is

good question that. i don't know but if memory serves i am guessing it is connected to his idea that cos we have an idea in our mind of the divinely perfect being of God that God therefore exists ( sounds a bit Platonic to me but still). You could look that sort of stuff up. not a lot of help that i know.

Thank you!

Or not as the case may be.

The quote is from Samuel Clarke.

On the god front, risibly, Descartes' desire was to establish truth rather than circular syllogism and 'I think therefor I am' puts the cart before the horse.