Ok, here's my attempt at an answer:

Take his statement: "I think, therefore I am."

My guess is that the way people interpret it is like this: Descartes is saying that he (notices that he) thinks, wbich (to him) implies that he must exist.

The statement can be broken down like this:

A, therefore B where A = "I think" and B = "I am".

But if you look at it like this: the "I am" part is asserting that he exists, which according to him is a logical implication of "I think". But his asserting "_I_ think" itself implies that his "I" exists (whether it thinks or not). So the "I think" is like saying "I exist" (and am also thinking - my emphasis is on the "I"). So it seems like he is already assuming something is true ("I" exist/am), on the left side of the sentence, what he is trying to prove ("I am"), on the right side of the sentence. Note the difference in the two uses of quotes in the last sentence. Hope I've made my thinking :) clear.

Thanks for this. :)

Indeed, I think I actually mostly agree with you. See my longer comment / explication of Descartes' argument (if it's an argument) above: I personally (also) think that "I think" already presupposes too much. What one might be able to argue is a lesser version of the thing, though:

thinking, therefore, existing. ("thought exists" (whatever that actually means!))

> So it seems like he is already assuming something is true ("I" exist/am), on the left side of the sentence, what he is trying to prove ("I am"), on the right side of the sentence.

..so yeah, I think that the only safe thing for him to say at that point would have been "thoughts exist." Maybe this does sound lame, but in the context of Descartes' Meditations, it's about discovering that even though you can doubt everything, this does require (the process of ) doubting as such.

Or: I can be deceived about everything there is in the world (so e.g. in actuality, there is no world as such); but who is being deceived? At the very least, there is (some kind of) thought happening. One might say that doubting requires an agent, etc., but really, this is already debatable.

But in short: you're right, if one were to establish "I exist" (with an "I" having certain desirable properties), one could then say "I think", and that would have been less murky, indeed!

Problem is, poor Descartes is not sure that he "exists":

indeed, for him (and this is partly to do with the whole mentality present in Rationalism, and with the start of Modern philosophy (many people hold him to be the father of it)) thinking comes before existing. You will find many parallels of the latter around, scattered in various places; cf. "god thinks itself into being", etc.

He kind of articulates one of the foundations of Rationalism as in the epistemology: thought shall be the ultimate and primary criterion for truth.

But again, I agree, however, I would say that he could have stated a lesser version of his point (while not reversing the logical implication arrow): "thoughts exist."

However, to go from that to re-establishment of certainty about the whole wide world would have been even more tough (and he was already having a hard time!) In summary, I think I understand where he's coming from, but one could say that his project (a kind foundationalist epistemology) had been doomed from the very beginning!

> Hope I've made my thinking :) clear.

Yeah, I think that was clear! Forgive me for my verbosity, and thanks for the explanation. I think it makes sense, and fwiw, I agree with the general gist of it.

No problem, and you're welcome. I agree that he could have asserted a lesser version, such as "thoughts exist", as you say. Interesting points, and good discussion, thanks!