Meh. I tried.

Have you tried reading his posts over and over again until you agree with him though? That's his recommendation.

You don't seem to know even the difference between validity and truth.

Yes thanks for the correction. It’s been a long time since I was doing logical proofs. Most of the time now I’m just coding in c / c++ / c#….

Right. Needed to add the boolean p truth phrase as well.

I believe my old friend Russel and Whitehead would balk at the soundness requirement for a true premise when confronted with gobbleydey-gook. Ergo my request for a real world example: In the mapping of reality to symbolic logic it seems like a very salient point to make. Should we not use the same soundness and completeness requirements for our mapping as we do within the closed logic system we are mapping to? Else those variables in use could in fact represent invalid states that would not be useful for inclusion in any computation.

In other words: you have to validate your inputs… usually a purify method is prudent when taking in data from the wild before you include it in your precious logic / code ;). After all you can’t let the wolves in - it’s bad enough they must already know where you live.

Yes thanks for the correction. — Metaphyzik

Yes no problem. I think your intuition was leading you in the right direction anyway, which is a good sign. Good logical intuition is valuable, because if you don't have it, your intuition leads you to thinking absurdities like "if it rained, the ground is wet; it didn't rain, therefore the ground isn't wet".

if it rained, the ground is wet; it didn't rain, therefore the ground isn't wet — flannel jesus

That is if a->b, then ~a->~b. Which is only true if you have a very limited and closed system or set to consider. Aka if there is no other way the ground could get wet, except for rain.

Aka the utility of formal logic depends on the validity / context of the parameters being used - their scope. So scope has to be verified and agreed on before logic can aptly be applied to anything really… else the outcomes will not be accepted anyways.

Typically these can be represented with other axiomatic inclusions… but when considering a mapping to reality it is easy to see how that fails at some point…. Just too many variables to take into account. Completeness is the eternal problem.

But the simple cogito? With 2 things that could be easily represented as Booleans? Formal logic does just fine without contradicting itself. I don’t think therefore I don’t exist is not in the truth table as the negation would also have to include the truth of thinking for inclusion - as you so rightly have pointed out

If there were no other way to exist other than to think, Banno would be correct in considering such a closed system. But I dont believe anyone would allow that axiom into the equation.

So you think of the Cogito as a poem, and are not convinced by it, but by the argument you find in it? — Banno

Descartes' arguments are a meditation. The meditation is expressed with words on a piece of paper. But it is not the words on a piece of paper — a poem —, put together validly with logical connectives in the form of English conjuctions, that prove my existence. It is when I exercise the meditation myself that I realise that I exist.

“Am thinking” says enough. — Fire Ologist

Indeed, Fire, he says in the beginning of the Second Meditation:

Wherefore I may lay this down as a Principle, that whenever this sentence I am, I exist, is spoken or thought of by Me, ’tis necessarily True.

And this article reaffirms it:

Finally, at the end of the paragraph he mentions the conclusion to be drawn when I think that I am something, namely, "I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive it." Such a conclusion is in effect a gloss on Descartes' own use of "ergo" and once again reference to the mode of thought has appeared twice. — Descartes, Russell, Hintikka and the Self

It is, on the contrary, or so Descartes would have it, in thinking and the certainty about itself that it entails that I at the same time become fully conscious and by the same token certain of my own existence as opposed merely to acquiescing in it more or less automatically even when I seem to be calling it into question.

In a letter to Bourdin, Descartes instead puts it as "ego cogitans existo". It is not so much that we take "I think" and then conclude "I exist", but every thought gives the certainty of existence. Which is why Descartes says, as quoted by Banno, that it is almost as if he would stop existing if he stopped thinking.

My overall impression is that logic is not a strong point hereabouts. — Banno

There are not many strong points in this thread.

they do if they are by definition thinking things. That's rather the point — Banno

Which I acquisced and clarified before, you say so:

you went into great lengths about the difference between extended substance and cognitive substance, but having to invoke dualism to solve this issue counts against the whole enterprise — Banno

I would hardly say that was a great length, but the proof of one's own existence does not depend on dualism. The mind-body dualism simply clarifies under what conditions something would cease to exist when it is not thinking. If something inherently thinks, it would not be anymore if it stops thinking. If X is inherently red, X would cease to exist were it to stop being red, aka it would stop being.

In particular, the bit where you stop existing when you go to sleep. — Banno

If we define dreaming as thinking too — which is an assumption that "stop existing when you stop thinking" relies on —, we don't stop existing when we go to sleep. Even if it were, there is a difference between ontology and epistemology. Descartes is trying to show how we can come to know that we exist, which is a different matter of under what conditions we exist. That I know that «I am» is different from «what it is that I am». He explores this also in the beginning of the Second Meditation:

Let me ask therefore what I am, a thinking thing, but what is that?

You mistook me for some other folks in the thread. — Corvus

Guilty as charged ¯\_(ツ)_/¯

If we agree to infer that Descartes Cogito's premise was I doubt everything — Corvus

That is not the premise, that is where he starts his investigation.

I doubt everything. (P1)
But I don't doubt Thinking. (P2) — Corvus

The two premises are contradictory. Not that it matters, because Descartes never said anything like this. I can only recommend reading Descartes.

Or it could just be a coincidence that the native speakers here are pointing out thattherefore is being taken by Corvus as causal and chronological, when in fact this is not the case, AND this is real possibility for native speakers of Korean to take the word in those incorrect ways. — Bylaw

That is one of the many mistakes he has made. I fully address it here:

Anyway, Descartes did not know English, he never went to England, he did not write in English. He wrote in French and Latin. The statements are "je pense donc je suis" and "cogitō ergo sum".
The Larousse dictionary is clear:

1. Marque la conclusion d'un raisonnement, la conséquence d'une assertion ; en conséquence, par suite de quoi : J'ignore tout de la question, donc je me tais.
"Donc" marks a logical conclusion. Je suis is the conclusion of je pense.

Ergo means the same as donc, Gaffiot 2016:
2 ergō, (5) conj. de coordination, donc, ainsi donc, par conséquent : Enn. d. Cic. CM 10 ; Cic. Fin. 2, 34, etc. || [avec pléonasme] : ergo igitur Pl. Trin. 756 ; itaque ergo Ter. Eun. 317 ; Liv. 1, 25, 2 ; 3, 31, 5, etc. || [concl. logique] : Cic. Fin. 2, 97 ; 5, 24 ; Læl. 88, etc.; ergo etiam Cic. Nat. 3, 43 ; 3, 51 ; ergo adeo Cic. Leg. 2, 23, donc aussi, donc encore

You see then it marks conclusion too. From "cogitō" I can conclude that "sum". — Lionino

Which he replied:

Conclusion is always consequent of the premises. You never conclude something, then list premises afterwards — Corvus

Then:

And the conclusion of "I think" is "I am". — Lionino

To which there was no reply.

I mean, even in English, "therefore" has most of the same meanings. As a consequnce, in conclusion, etc. It's totally understandable to go to the original French, but it really ought not to matter - we know what "therefore" means in English (by "we" I mean apparently everyone except Corvus), and it clearly includes the definition about introducing a logical conclusion.

https://www.vocabulary.com/dictionary/therefore#:~:text=(used%20to%20introduce%20a%20logical,reason%20or%20as%20a%20result

The guy has a narrow understanding of a word in a language that isn't his first language, which is understandable and I don't fault him for that - the part that isn't understandable, that I do fault him for, is that he has absolutely 0 humility about it. He refuses to hear, from native English speakers, that "therefore" has different uses than what he insists it must mean.

The whole ordeal is a never ending illustration of the Dunning Kruger Effect

But the simple cogito? (…) If there were no other way to exist other than to think…. — Metaphyzik

If it is I that thinks and given that there is thinking, then isn’t it necessary for “I” to be? Under these conditions, there is no way for “I” to be other than to think. Descartes used the term “exist” here and there, for which he should be forgiven, considerIng the general mandate of his thesis.

“…. This is the best way to discover what sort of thing the mind is, and how it differs from the body. How does it do that? I am supposing that everything other than myself is unreal, while wondering what sort of thing I am. I can see clearly that I don’t have any of the properties that bodies have—I don’t have a spatial size or shape, and I don’t move—because those properties all fall on the supposed-to-be-unreal side of the line, whereas we’ve just seen that I can’t suppose that I am unreal. So I find that the only property I can ascribe to myself is thought. So my knowledge of my thought is more basic and more certain than my knowledge of any corporeal thing.

….I take the word ‘thought’ to cover everything that we are aware of as happening within us, and it counts as ‘thought’ because we are aware of it. (…)

….I’m not going to explain many of the other terms (in addition to ‘thought’) that I have already used or will use later on, because they strike me as being sufficiently self-explanatory. I have often noticed that philosophers make the mistake of trying to explain things that were already very simple and self-evident, by producing logical definitions that make things worse! When I said that the proposition I am thinking, therefore I exist is ‘the first and most certain thing to occur to anyone who philosophizes in an orderly way’, I wasn’t meaning to deny that one must first know what thought, existence and certainty are, and know that it’s impossible for something to think while it doesn’t exist, and the like. But these are utterly simple notions, which don’t on their own give us knowledge of anything that exists; so I didn’t think they needed to be listed…”
(Principia Philosophiae, 1, 8-10, 1644, in Bennet, 2017)

I gather that he is making mistakes in symbolic logic also, but that's not something I'm as familiar with.

I just found this so galling...

You totally distorted the meaning of the word "Therefore" in your claims. Therefore means by the result of, for that reason, consequently. Therefore it has implications of chronology and cause and effect transformation for the antecedent being the past, or cause, and the descendant to imply the result, consequence and effect.

If you deny that standard meaning, then you are denying the general principle of linguistic semantics. And that is what you have done to mislead the argument and further present the nonsense.

I mean, this is precisely an error a native speaker of Korean can make. It's easily forgivable that he makes that mistake. It's easy to find out this is a problem coming from Korean, and that there are two words used to translate 'therefore' one much closer to this use in the English cogito (and also donc in the French version). Several different native speakers are telling him he is misunderstanding the word. And when it's pointed out he tells me I am not using the standard definition. Well, there are a few ways to use 'therefore' in English.
Just for thoroughnessI'll like to what you're responding to of mine: https://thephilosophyforum.com/discussion/comment/892205 and which you linked to.

Earlier he told Flannel Jesus that he could look in any logic textbook and find that his denying the antecendent was correct. Yet recently he chided Banno for citing logic books. And he never got around to showing us how his logic book said he was correct. But when a logic work (supposedly) supported his position, it was fine to point this out. (though never to get around showing us that it did). I don't understand the language. Banno doesn't understand the difference between truth and validity. Flannel Jesus doesn't understand....and on and on.

I do often wonder how conscious people are of what they seem to be avoiding admitting (to themselves? to us?) that maybe, just maybe other people might have a point. Conscious or not I think there are dozens of examples of disingenousness in this thread.

If it is I that thinks and given that there is thinking, then isn’t it necessary for “I” to be? Under these conditions, there is no way for “I” to be other than to think. — Mww

True!

Was thinking of a simpler model I guess:

If x thinks, then x exists.

And I guess if x is in a coma and is not thinking - or is successfully meditating then x would not be currently thinking (but capable of thought)

It's totally understandable to go to the original French, but it really ought not to matter — flannel jesus

True.

and no one has set the inference out for us in a valid way. — Banno

:roll:

I wonder why you chose Korean specifically. But take a look at this https://thephilosophyforum.com/discussion/comment/857740

and it clearly includes the definition about introducing a logical conclusion. — flannel jesus

Yes, exactly. Yes, it can be used in other ways, but here it is not
first part of sentence comes earlier in time ontologically than what is mentioned in the second part.
Any chronological is about one being able, when one notes the first, to conclude that the second was also present at the time of the thinking.

It's a basic misinterpretation of therefore in this context. Discussions by philosophers of the cogito will show that they all get this and interpret therefore and donc in a way different from Corvus. Corvus is a non-native speaker. In his language it is easy to mistranslate therefore to a words that has the meaning he projects on to the English word (and the French word also). There is another way to translate it into Korean that is better, and so on.

Instead of for one second considering he might be misinterpreting the term and exploring that for a bit, he accuses me of leading everything into nonsense.

↪Bylaw I wonder why you chose Korean specifically. But take a look at this https://thephilosophyforum.com/discussion/comment/857740 — Lionino

I searched his posts for something else and found him saying he was Korean. So, I did a bit of research to see if 'therefore' might cause problems for a native Korean speaker. And lo......

in a post in response to you in fact...

I tried reading Philosophy in Korean which is my native language, but it was actually more difficult to understand. I think problem is the translation.

I figured.

And I guess if x is in a coma….. — Metaphyzik

Anthropomorphic tautologies with respect to x aside….on the off-chance you weren’t actually going there….the coma thing won’t work, if we’re keeping with the original cogito simpliciter you started with, in that Descartes counts thinking as such “because we are aware of it”.

Relevant for the matter of Descartes' argument being an inference:

From this same article https://www.jstor.org/stable/40694016 . The second half with Gassendi is much more interesting than the first about Russell.

It is notable how much scrutinity Descartes' philosophy has received.

Ok ;)

My point was really more about the context

That is not the premise, that is where he starts his investigation.

I doubt everything. (P1)
But I don't doubt Thinking. (P2)
— Corvus

The two premises are contradictory. Not that it matters, because Descartes never said anything like this. I can only recommend reading Descartes. — Lionino

Far more wild premises are made up and forwarded as some reasons why the contradiction reasoning is not the case by the other folks. Those are not said or written by Descartes, but they are reasonable and interesting inferences for the premises of cogito.

In logical arguments, premises are made up with reasonable inferences and assertions. Nothing like talking about hosing a garden, when the argument was about the rain and wet ground.

If Descartes had said or written about the basis for cogito, then no premises would be necessary. Because the only basis for cogito was his doubt on everything he perceived, the premises from the reasonable inferences were asserted in the post.

I wonder if you read any Descartes at all yourself.

But he says in the Second Replies:

Cum autem advertimus nos esse res cogitantes, prima quaedam notio est, quae ex nullo syllogismo concluditur; neque etiam cum quis dicit, ego cogito, ergo sum, sive existo, existentiam ex cogitatione per syllogismum deducit, sed tanquam rem per se notam simplici mentis intuitu agnoscit, ut patet ex eo quod, si eam per syllogismum deduceret, novisse prius debuisset istam majorem, illud omne, quod cogitat, est sive existit; atqui profecto ipsam potius discit, ex eo quod apud se experiatur, fieri non posse ut cogitet, nisi existat.

But when we notice that we are thinking things, there is a certain first notion, which is concluded from no syllogism; nor even when someone says, I think, therefore I am, or I exist, he deduces existence from thought by a syllogism, but recognizes it as a thing known in itself by the simple observation of the mind, as is evident from the fact that, if he deduced it by a syllogism, he must first have known this greater , everything that thinks is or exists; but surely rather he learns himself, from what he experiences with himself, that it cannot be as he thinks unless he exists.

About that:

And more generally it determines his [Descartes'] preference for demonstration by analysis which is supposed to reflect the order in which truths are actually discovered as opposed to demonstration by synthesis which he seems to identify with the axiomatic method, axioms being a proper sub-set of general principles.

↪Bylaw I figured. — Lionino

His wild imagination has no ground. Just someone said his native language is Korean doesn't prove that he is a Korean. His repeated meaningless citing on the point is very strange and irrelevant for the discussion. If you listen to him, and thinks it makes sense, it proves that you have no ability to reason.

OK. Thanks.

Do you agree or disagree with this logic?

If red light, then drive away. R -> D
If not red light, then don't drive away. Not R -> Not D is False
Therefore If red light, then drive away. R -> D is False

but they are reasonable and interesting inferences for the premises of cogito. — Corvus

They are not, which is why no scholar says Descartes' argument is contradictory.

I wonder if you read any Descartes at all yourself. — Corvus

On what basis do you have this wonder, since you have basically admitted that you didn't read him at all?

If red light, then drive away. — Corvus

That is an order, it has nothing to do with logic. It is not how A→B is used.

then interpret it as an order, that's fine.

If it's red, then the order is to drive away.

If it's not red, then the order is to not drive away, apparently

i don't know if he's saying that's a second, separate order or if he's saying that follows from the first order. Obviously to most people here (all except one), it doesn't follow from the first. You can order them to drive away if it's red and not order anything at all if it's not red, there's nothing wrong with that.

He's still just searching for new ways to deny the Antecedent. No idea why, he knows he didn't find it in his textbook.

They are not, which is why no scholar says Descartes' argument is contradictory. — Lionino

The only basis for your claim, they are not, is because no scholar says D's argument is contradictory?

On what basis do you have this wonder, since you have basically admitted that you didn't read him at all? — Lionino

Your claims on D seem to be based on some type of religious beliefs rather than academic theories.

If red light, then drive away.
— Corvus

That is an order, it has nothing to do with logic. It is not how A→B is used. — Lionino

Any event which can be described in human language can be translated into the formal logic. It is called propositional logic.

Here's a fun syllogism in the style that Corvus likes:

If he could find that denying the Antecedent is valid in his textbook, then it's true that it's valid.
He couldn't find it in his textbook.
Therefore
it's not true that it's valid.

The only basis for your claim, they are not, is because no scholar says D's argument is contradictory? — Corvus

The basis for my claim is that I have read Descartes and that is not his argument. If that were his argument, some scholar would have picked up that his argument is contradictory, but that never happened, because that is not his argument.

Your claims on D seem to be based on some type of religious beliefs rather than academic theories. — Corvus

That sucks. But I have read him, the scholarship around him, the objections to him. I recommend you at least watch a series of lectures on him, there are plenty of uni channels on Youtube, so at least you stop embarassing yourself.

Any event which can be described in human language can be translated into the formal logic. It is called propositional logic. — Corvus

Interesting, please translate the following into propositional logic:
"If you had been there, you would have seen that the fireworks went off at the same as the bell rang."