Hmm. I don't think so, but, feel free to expand your opinion (why do you think it should be "I am, therefore I (can) think"? Maybe you have an interesting point to make?)

Re: etymology, it's pretty much "think => exist."

Re: conceptual level: well, one of the texts where this whole concept/causal-chain is introduced is in his "Meditations on First Philosophy"[1], in particular, in Meditation 2.

Very (very) roughly (and from bad memory), the idea is that one can first start casting into doubt everything that there is (skepticism as a method) (this is Meditation 1.) When you abstract enough times, you can start doubting even the certainty of things which may seem true in themselves (this latter notion is an endless field of debate in itself; see e.g. Quine's "Two Dogmas of Empiricism"[2]) - cliche example is "2+2=4."

Say there's a deceitful daemon: each time the thought "2+2" is produced, the daemon "intercepts" the answer and produces a "5". (Yes, I'm saying that Descartes may be one of the originators of the concept of a MitM, ha!) (Also, this doesn't work so well with mathematics, since again, one could say that mathematical statements are "analytically true", and it's simply not true that one may mistake a "5" for a "4". But imagine something more mundane: each time you think if there is a god, the daemon deceives you into thinking there isn't one; whatnot.)

So now you generalize the doubt process enough to start doubting whether anything exists, what-so-ever. The point is not so much in thinking that there isn't anything, but in removing certainty from usual ontological assumptions (what (kinds of) things exist.)

So now you're not certain if there is an "I": you are able to doubt it.

But then Descartes says that this very process of certainty-removal requires an operation (he doesn't use these words, did I say this is extremely rough): namely, the "doubt" itself. "Doubts are to be had."

Or, if you will (and closer to D. (I think)): if an evil daemon can cast into doubt even the existence of your own self - it it can deceive everything, etc. - there needs to be a something to be deceived. Or at the very least, the process of deception (or: of doubt) does happen (if you want to cast everything into doubt.)

So if you doubt that anything exists and hence can not be certain of anything, then it so happens that this requires doubt "to happen." Hence "doubt exists." (He also says (I think) that, basically, "clearly since I am doubting right now, doubt does happen". A kind of phenomenological argument, which doesn't really stick with me, fwiw. He then starts using the notion of "clear and distinct perception", and that's where things go downhill imho (Meditation 3, a (kind of circular) proof of God, etc.) But I have few qualms about Meditation 2, and this includes cogito ergo sum.)

(You could say that the only thing one can be certain of is that "there are thoughts" (not an "I"). I would agree with this. "Thinking exists." And since "thinking" would be, well, thinking this thought, it is certain that "thinking exists.")

edited to include two paragraphs (this+next one): So now we (hopefully) have something that exists for certain; thoughts exist (or somesuch.) Descartes claims a bit more: this entity that does the thinking (there does need to be an agent which thinks those thoughts (is what he assumes, I guess)) - let us just say it is "I", who does the thinking/doubting - when we trace back the process by which we concluded that we are certain that it exists - involves us discovering that thinking/doubting definitely does take place. Hence "I think; I exist."

(I suppose you could have a concept of an "I" that is simply instrumental (doesn't have independent substance (oof, this is dangerous/slippery territory)): thoughts can have relations, and related thoughts can be seen as "bundles", and this process producing continuing interrelated bundles is "the I doing the thinking." But, I'm not sure of this at all. Maybe D. would say that the deceiving daemon needs to deceive something, if it does actually do any deceiving; and if this does happen, then this "something" which is being deceived is (let us call it an) "I".)

Now, to go from cogito ergo sum to proof of God and subsequent re-establishment of certainty about the whole world - that is something else. And I don't think that he does a very good job at it. (And this is "usually", "generally" agreed upon.)

[1]: https://en.wikisource.org/wiki/Meditations_on_First_Philosop... - which btw is an easier read than you might think, if you're curious enough!

[2]: http://www.ditext.com/quine/quine.html

>Hmm. I don't think so, but, feel free to expand your opinion (why do you think it should be "I am, therefore I (can) think"? Maybe you have an interesting point to make?)

I did say "vaguely". Let me think about it a bit and then reply later tonight.

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!