One can find all sorts of other stuff that one cannot coherently deny - like that you are reading this post. So if that is our standard, the Cogito is hardly special. — Banno

I can coherently deny any sense data, like reading “this post”.

But I can’t deny to myself that I am reading, or at least that I think I am reading. (Hence Descartes’ use of “I think”.)

But you just said “the Cogito is hardly special” based on it showing something one cannot coherently deny. BUT, you asserting that the Cogito isn’t special won’t work for you to argue that the Cofito is meaningless. You just asserted it has a non-special meaning.

I don't know what you are asking. Shouldn't that be (¬t→¬e) → F? Which is not valid, as shown by the countermodel. — Banno

If you don't think, you don't exist. Is this not False?
Even if you don' think, but you still do exist. No?

I can coherently deny any sense data, like reading “this post”. — Fire Ologist

You replied to the post. Now you would deny that there was a post, and supose this to be somehow coherent?

I have not claimed that the cogito is meaningless.

I commend On Certainty to you.

If you don't think, you don't exist. Is this not False? — Corvus

There are things that... and here one needs a free logic... that don't exist and don't think.

But you have gone off on a tangent, I asked if you would explicitly deny that (t→e)→(¬t→¬e).

There are things that... and here one needs a free logic... that don't exist and don't think. — Banno

But here are we not talking about "I"? - "Cogito"? We are not talking about rocks and bricks here.

But you have gone off on a tangent, I asked if you would explicitly deny that (t→e)→(¬t→¬e). — Banno

Of course I deny its Truth. It is FALSE. That is one of the proofs (t→e) is FALSE. But there are so many other reasonings that can be applied which makes t->e is false.

If we agree to infer that Descartes Cogito's premise was I doubt everything. Then,

I doubt everything. (P1)
But I don't doubt Thinking. (P2)
Therefore I think, therefore I am (C)

Then Cogito becomes invalid.
Doubt is also type of thinking, which makes P2 false.

The core problem here is that, mental event Think cannot leap into 100% certainty of verified Truth of one's existence. They are different class in existence. Think is a mental event. Existence is a physical object.

I have not said that the cogito is meaningless. — Banno

Then I don’t know what you are arguing with me about. I already said I’m not interested in the gaming of logical analysis of “I think; therefore, I am.” That whole conversation is an exercise in missing the point the feeble statement is trying to show, a point that any 10 year old thinks is so obvious it allows them to laugh at philosophers.

I know that I am while wondering what is, and I can’t unknow this.

It’s not about the “I”. It’s not about the “therefore”. It’s about the “am” present in “think”. “Am thinking” says enough.

It’s a premise more than a conclusion, so certainly no argument is needed.

If you disagree with me I can only assume you might not exist to check my math.

It’s not about the “I”. It’s not about the “therefore”. It’s about the “am” present in “think”. “Am thinking” says enough. — Fire Ologist

But if you cannot prove, or refuse to prove your claims of "Am thinking", it means nothing to anyone apart from to yourself. It would be like talking about your last night's dream.

Of course I deny its Truth. It is FALSE. — Corvus

It's not false - if by that you mean that it is a contradiction and false for every interpretation.

(t→e) tells us nothing about (¬t→¬e).

(t→e) tells us nothing about (¬t→¬e). — Banno

How is it tell you nothing? It is a result from the principle of contradiction in proof process.

If it rains, then the ground is wet.
It doesn't rain.
Hence the ground is not wet.

How is it tell you nothing? They are the reasoning from contradiction.

If I think, then I exist.
If I don't think, then I don't exist. ???? False.
Hence If I think then I exist. Is False.

If it rains, then the ground is wet.
It doesn't rain.
Hence the ground is not wet. — Corvus

In Corvus world, there's only one way for the ground to get wet. That's the absurdity of taking p->q to imply notp -> notq - everything can only happen in one way, every property can only exist in one thing.

If you're arnold schwartzanegger, then your muscles are big.
You're not arnold schwartzanegger.
Therefore your muscles aren't big.

It's a hilarious type of reasoning really.

That whole conversation is an exercise in missing the point... — Fire Ologist

So you are certain of the Cogito without any justification?

How is it tell you nothing? — Corvus

Because (t→e) can be true and yet (¬t→¬e) either true or false.

He thinks implication is equivalence, it seems.

I have to go water the garden. It's not going to rain today.

He thinks implication is equivalence, it seems — Banno

Yes, that's what I was getting it when I was comparing it to a <-> b.

If all instances of implication p->q also mean notp -> notq, then all p->q are really p <-> q.

Which is kinda broadly similar to equivalence, I suppose.

How is it tell you nothing?
— Corvus
Because (t→e) can be true and yet (¬t→¬e) either true or false. — Banno

(¬t→¬e) is definitely False in the Cogito case, which makes (t→e) False too.
No one with right mind would agree that, when he stops thinking, he ceases to exist.

In Corvus world, there's only one way for the ground to get wet. — flannel jesus

I recommend sitting back and observing whether or not Banno can get through to Corvus. Here, have some popcorn.

you're right, I should. Crunch crunch

Ok. This is why we can't have nice conversations on these forums.

...which makes (t→e) False too. — Corvus

No, it doesn't.

You have been battered about this for a few days now, and it is difficult to back down when you make a mistake, even in the most friendly circumstances.

But I really do have to go water the garden. You see,

If it rains, then the ground is wet.
It doesn't rain.
The ground is not wet.

and

If I don't hose, and it doesn't rain, the ground will not be wet

But

If I hose, the ground will be wet.

All I did was remove "Hence". That's were you went astray.

You have been battered about this for a few days now, and it is difficult to back down when you make a mistake, even in the most friendly circumstances. — Banno

If that is how you see it, you are wrong. I am only interested in the philosophical discussions based on reasoning. Nothing else will interest me in this forum.

I don't care about some inauthentic time wasters throwing nonsensical abuse in the thread. I have decided to ignore them totally. I have not been battered by what appear to be nonsensical tantrums motivated by some of their psychological problems.

If I don't hose, and it doesn't rain, the ground will not be wet

But

If I hose, the ground will be wet.

All I did was remove "Hence". That's were you went astray. — Banno

Of course everyone knows that.
We are talking about the a logical progression started off from a specific premise in the argument.
It is about whether the conclusion is derived from the premises.

If you deny that and bring out some irrelevant argument, then there is nothing in the world which can be proven on the empirical issues.

If you hose your ground, so the ground will be wet.
But that is false, if the water gets dried out in few hours under the scorching sun.

I was under impression you would be good at logic and proofing, but taken back at your inability to understand even what simple logical proof process means. Bringing out some irrelevant premises into the argument to the conclusion drawn from the set premises and denying the validity of the proof is a sign of misunderstanding of the very basic foundational principle of the subject.

I recommend sitting back and observing whether or not Banno can get through to Corvus. — wonderer1

It seems not, but

Are You Not Entertained? Is this not why you are here?? — Maximus, and Banno

It seems not, but
Are You Not Entertained?
— Maximus, and Banno — Banno

I am. :nerd: Banno claims that he ceases to exist when he doesn't think. :rofl:

Are You Not Entertained? — Maximus, and Banno

Hoping to be edified.

, from "If it thinks, then it exists" it does not follow that "If it does not think, it does not exist".

And from "If it rains, the ground will be wet" it does not follow that "If it does not rain, the ground will not be wet". I can hose the ground, and rocks exist without thinking.

Hoping to be edified. — wonderer1

Why - because that would be entertaining?

from "If it thinks, then it exists" it does not follow that "If it does not think, it does not exist". — Banno

It is not about follow. It is about introducing assertion and inference.

And from "If it rains, the ground will be wet" it does not follow that "If it does not rain, the ground will not be wet". I can hose the ground, and rocks exist without thinking. — Banno

Are you still claiming that when you stop thinking, you cease to exist is true? I am saying that is False.
Rocks existing without thinking is totally irrelevant. It doesn't rain, then the ground is not wet was given as an example to let you see, that Not t - > Not e is telling something, not nothing.

However, we are talking about Cogito (I think) here.

Why - because that would be entertaining? — Banno

No, because if you are able to get through to Corvus, observing how you did so might provide me with insight that I don't have at present.

It is not about follow, it is about introducing assertion and inference. — Corvus

Yes, Follow.

Are you still claiming that when you stop thinking, you cease to exist is true? — Corvus

No, Corvus. That is your confusion. I have never claimed that when you stop thinking, you cease to exist. What I have said, quite explicitly, is that if Descartes' argument is that if you are thinking, you exist, then that this does not, as you have claimed, imply that if you stop thinking you cease to exist.

I have also attempted to show you that your argument would hold if Descartes' argument is that by definition "I" am the thing that is doing the doubting. This is your out; but it seems you have difficulty seeing it.

You bite the hand...

Are we now playing "posts last wins"?

No, because if you are able to get through to Corvus, observing how you did so might provide me with insight that I don't have at present. — wonderer1

Previous experience has shown that Corvus will not correct his errors nor accept any interpretation not at one with his own, apparently now to the point of extremis.

On the other hand, he has quite successfully made this thread about himself. A tragedy in which we are all implicated.

We were moving on a bit, until became involved, leading us back into the mire.

Are we now playing "posts last wins"? — Banno

No, that is not my game. You mistook me for some other folks in the thread.
I am just trying to understand your logic here. There are parts in your claims which is not crystal clear.
I will think over, and will return with my thoughts on your point. Enjoy your gardening. Cheers mate.

I am just trying to understand your logic here. — Corvus

It's not just my logic.