Please remember. The classic symbolic logic works on the forms only. No contents. I have several Logic books at home. And they all say the same thing. You must get any symbolic logic books, and have a look into them. It will all be there.

This is the simplest logic. There is nothing much to it. Why you cannot see my point is beyond common sense.

It gives me impression that if you were found that your point was wrong, then you seem to be reverting back to ad hominem, or you haven't read what I said replies. That is why I feel that you and your pal the wonderer are inauthentic.

OK we had enough discussions on it. I will leave you to it. Good luck.

In symbolic classic logic, the contents don't matter. It works purely on the format.
So if you say,
P-> Q
Not P
Then it must be Not Q

There is no way Not P, and it is still Q.

The proof process goes on with introducing negations, assertions and inferences. That's why it could have Not P for the negation introduction. If Not P, then it must be Not Q.

But Not Q doesn't make sense. You confirmed that it is incorrect. Hence P->Q is incorrect.

You think, but sometimes you stop thinking. But you still keep existing.
Not thinking doesn't make you non-existence. You think therefore you are. is logically incorrect.

I hope this helps.

Sure, present your argument against it, if you have any. I must go and do some work. I will read it later.

Well, if you say it is incorrect, then you proved yourself, you think therefore you exist is incorrect too. That is a simple logic.

No it is not. You don't agree with that, is psychological. It is incorrect is factual.

Is it correct or incorrect?

Why do you refuse to answer to a simple question?
You don't think, therefore you don't exist. ==> Is this correct?

Because you couldn't understand the most basic demo of logic, I had to ask you in ordinary language about the point. You change the subject, and refuse to answer.
So, the only conclusion I can have is that, you are not an authentic interlocutor. Please read some books on the topic before engaging in the discussions.

You still refuse to answer. You are not an authentic interlocutor.

Don't change the subject. Please answer me.
You don't think, therefore you don't exist?

Obviously you have not read a single Logic book, but are copying and pasting some internet info here. So I shall not try with logic. In simplest ordinary language, If you don't think, you don't exist? You don't think, therefore you are not?

You can use MP using negation too. Please read some introduction to Logic.

What is there to misunderstand? It is the simplest symbolic classic logic. Only thing is your trying to distort the truth even I have shown the clearest logical proof.
It seems that even the simplest logical demo is not getting through to you. Only thing I could ask you is keep reading my posts, and think clearly until you can understand it.

Are you prepared to listen to find out why? — flannel jesus

Sorry. I have already explained in most clear logical way with even the simplest symbolic logic Modus Ponens demo example. If you still cannot see it, then I can no longer do any further. I shall not waste any more of your time or mine with this point. Have a good weekend jesus.

You really should stop. — Lionino

Just been pointing out the problems. :nerd:

I am is necessary for I think. — Lionino

That is an irrational leap. It doesn't follow logically. If it is necessary you are for you think, then what is the point saying therefore you exist? It sounds redundant, circular statement, and doesn't prove anything.

By the way, it is necessary T in symbolic logic writes □T. Not ¬(¬T)

There's a reason both of us think you've got it backwards here. You aren't being completely rational here. You DO have it backwards. — flannel jesus

P --> Q
¬P
=====
¬Q

Your claims that "you think therefore you exist", deduces "If you don't think then you don't exist."
A simplest symbolic logic based on Modus Ponens demonstrates you guys claims are a contradiction.

No, it is the same mistake over and over and over. The newborn does not think, but it exists, existence does not imply thought. You are confusing explanation with causation. — Lionino

The whole point is so simple, but you seem to be trying to make it complicated needlessly for some reason. The point is that you don't need to think to exist. Existence doesn't need thoughts. It exists, because it does.

Was SJ a stoic?

That's fascinating. Thank you. — Truth Seeker

:grin: :pray: :pray:

I think because I am, which is incorrect, as we know, because, unless you are a panpsychist, you think not because you are but because of many reasons, including that you are.
This is definitive proof that cogitō ergo sum is not inverted. Farewell, さらばだ. — Lionino

If you still insist that "You think therefore you are." is correct, then when you were just born, and was not able to think, does it mean that you didn't exist? What a contradiction.

Time to wake up from the slumber mate. :D

I didn't say for certain. For the fourth time, I said it not logically necessary that there is life in Mars. You need to research what logically necessary means. — Lionino

I have no idea what's your fascination with logical necessity, and keep repeating yourself with the term here. The point is that is not relevant to your statements that you know life doesn't exist in Mars, or Cogito.

No, because that is not what the word "therefore" means. You are thinking of "I can only come to think if I exist", which is exactly Descartes' point. The city is wet, therefore is rained. I am sneezing, therefore I have a virus. In X therefore Y, Y is the cause, X is the consequence.
You are simply getting confused with the meaning of words. — Lionino

This seems the real confusion and linguistic muddle.

Funny that you say Descartes got something wrong when we both know you have not read Descartes. — Lionino

I don't need to read the whole Descartes to know that his main theme in Philosophy is illogical. No one needs to.

A mere fact that you don't know something does not mean that something doesn't exist. It isn't too deep knowledge to understand. To someone with no senses, everything might sounds nonsense. Hope it is not the case with you.

There is nothing more to add apart from asking you to re-read my posts again.

Ah yes, the never ending pool of knowledge about "unknown existence" lmao. What a conversation-ender. — flannel jesus

If you think about it, there are many unknown existence in this world. Until you know about them. Why is it so difficult to see?

I cannot roll my eyes hard enough at this non-answer. — flannel jesus

Well flannel, if you try think clearer, perhaps you could see better. It is not all that easy to understand the deep knowledge and logic, suppose. :chin:

I took the thirsty horse to the river. It is now up to the horse to drink the water, or keep suffer from the thirst. I can do no more afraid.

And one more thing - I forgot to add, is that we are all existence on the road according to M. Heidegger. Even if, we feel and it looks as if the world and us are stationery, we and the world are on the non-stop journey. A journey to the end of the visit to the earth to the unknown destinations.

If you agree that something can't think unless it exists, then "I think therefore I am" ought to make sense. Do you think something can think without existing? — flannel jesus

There are two types of existence. The known and unknown. Unknown existence can be like non-existence. In that sense, yes unknown existence which is perceived to be non-existence can think.

The assumption is borderline SYNONYMOUS with "I think, therefore I am". The two statements seem like alternate phrasings of the same idea. One is just a little more poetic. — flannel jesus

No it is not. They are reverse in the cause and effect. They are not synonymous.

Thank you for your advice. You didn't answer my questions about your worldview. Why is that? — Truth Seeker

You are very welcome. Sorry for not having answered your question. Well actually I don't have a worldview of my own. That is why I am keep reading philosophy and psychology.

If I had my own world view, then I would go up into a mountain, and start meditating. Not yet. I am not sure if it will ever happen. But who knows. We keep on trying until our last days. Now that is a philosophy. :nerd:

And one more thing - sometimes no answer can be the best answer in Philosophy and the World.

The assumption I'm referring to is "Before thinking takes place, something must exist". This assumption and "I think therefore I am" are compatible, more compatible than "I am, therefore I think." — flannel jesus

The assumption "Before thinking takes place, something must exist." eradicates need for saying "I think, therefore I exist."

"I am, therefore I exist." was introduced to notify the reverse is false.

Yeah, that's what everyone else thinks except you. "Cogito ergo sum" works with that assumption, your reversal of it does not. — flannel jesus

Who is everyone and where is the assumption? What reversal are you talking about? I was only putting the cart behind the horse, of which Descartes put in front.

My worldview is evidence-based. If I become aware of incontrovertible evidence for the existence of souls and gods, I will stop being an agnostic atheist and become religious. I have researched the top twelve religions on Earth and none of them are evidence-based. This is why I am an agnostic atheist. I am open to new evidence e.g. if you show me incontrovertible evidence for the existence of fairies, I will stop being an agnostic afairyist. Do you understand my position better now? What is your worldview? What is the basis for your worldview? — Truth Seeker

If you read Kant's CPR, then he says our knowledge has limits. We don't have to know everything with 100% of certainty. Trying it would be futile exercise. Because our reasoning has antinomies. It is limited. And moreover, much of the needed data is not available for us to know things with certainty.
So that is a fact. You must accept that. And move on. If you read Kant, and understood the points, then you would either want to move up to Analytic Philosophy, Phenomenology or Existentialism.
If you mastered all these subjects, then maybe you would look into Religious philosophy.

You know that Religious topics are in different world which cause and effect principles work different way to the ones in the empirical world. You will then use your faith and intuitions rather than reason and logic for your analysis and observations for the subjects you want to enquire.

No. Plenty of things presumably exist which don't think. — flannel jesus

We are excluding the existing things which don't think in the discussion. We are only talking about the existence which thinks i.e. humans in here.

Before thinking takes place, something must exist. Thinking is not prior to existence. Thinking is a posteriori of existence. Descartes got it wrong, and is in deep confusion in this Cogito ergo sum muddle.

Ah, so then let's reword your previous question: — flannel jesus

The two different perspectives, the perspective of "being" and the perspective of "becoming" (process), each if taken to account for the totality of reality are reductionist. — Metaphysician Undercover

There are a variety of ways that happens. One way is, in medical science, you conduct a double blind study with placebo on the efficacy of a medicine in treating an ailment, you publish your study, and then other people can go on and repeat that study. Eventually, in successful cases, the studies are so successful that the rest of medical science comes to be convinced that that medicine does in fact effectively treat that ailment, and that's how it goes from personal knowledge to "objective knowledge". — flannel jesus

Yes, it seems a good explanation for the process of objectifying some subjective knowledge.

Not all things you might call "objective knowledge" happen in simliar ways. That's just one possible, but relatively common, narrative. — flannel jesus

There must be also the underlying principles for objectifying subjective knowledge such as "consistency" of the knowledge. For example, when Newton saw the apple dropping from the tree in his garden, he induced the law of gravity. At that moment of time, it must have had been his own subjective knowledge. But through the objectifying processes, it became an objective scientific knowledge ever since.

There must be "consistency" in the details of the knowledge for that to happen. If apple dropped in Japan, and it kept on floating in the air instead of falling down to the ground, or landed in the kitchen table by itself as soon as it dropped, then it couldn't have been accepted as an objective scientific knowledge or law. But it must have been falling down straight onto the ground as soon as apple dropped from trees wherever in the world, that consistency of the movement was the base of the objective knowledge.

I was wondering if there would be any other conditions like that in the process of subjective knowledge becoming objective knowledge.

what do you mean by "objective knowledge"? — flannel jesus

Objective knowledge just means that it is the agreed knowledge publicly or academically. If you went to the garden, and found something scientific for the first time in history, and you are the only one who knows about it, then it is a subject knowledge.

If you can't notice how this is completely different from Descartes' argument, this is beyond my powers. — Lionino

It was a reply to your irrelevant sentence, you know for certain there exist no life in Mars. It is strange for one to deny any knowledge on what one said, and got replied to.

Think is a verb, psychological is an adjective, exist is a verb, ontological is an adjective. You classified one as the other. Ok, so what? And the classification is faulty, ontology is a field of philosophy, psychology is a (pseudo-)science, you don't classify loose verbs as "psychological", it is gibberish. — Lionino

It is not a gibberish. It is saying that "Think" is a psychological concept, and "Exist" is an ontological concept. There is no logical transition between the two. It is an irrational leap to say "Think", therefore "Exist".

Thinking does not happen if there is no existing. Existing happens every time there is thinking. Thinking implies existing. I think therefore I am. Not the other way around. — Lionino

That is why it has to be (at a generous stretch) "I exist, therefore I think." No?

No, that makes no sense, existence does not imply thought. — Lionino

Existence comes first. Logically, and ontologically.

Ok, time to sleep. — Lionino

Perhaps your lack of sleep was making you feel everything hazy. Sleep well and sweet dreams. :nerd:

You have to look up what "logical necessity" is. — Lionino

You are talking about totally something else. The point is how your point for getting lot of backings implied, the popular media backings rather than logical backings. Because you had not shown any.

Yeah, and one implies the other. As Descartes and the editors have already explained, you can't think without existing, one thing begets the other. — Lionino

Then he should have said, "I exist, therefore I think." He obviously misunderstood something.
He put the cart in front of a horse.

Sum, ergo cogito, makes sense. But it doesn't say anything new or exciting, does it? Moreover, it is a circular statement. How the hell does he know that he exists? He was supposed to doubt everything.

Just because you arbitrarily put two verbs into two boxes that are just adjectives, it does not mean anything. If it were obvious you would be able to explain yourself very easily, but there is no argument. — Lionino

Now I don't understand here. What do you mean?

You would be surprised. — Lionino

At your misunderstandings :)

I also have no clue what this means. — Lionino

Nothing obscure in there at all. :nerd: