If existence is required for thought, then "I think therefore I am" makes immediate sense, don't you think? If someone agrees that "I must exist in order to think", then the cogito becomes an obvious consequence. — flannel jesus

So it's an intuition.

Is that sufficient for the foundation of knowledge? No. If someone has an intuition that folk born under Pisces are natural leaders, you'd throw it out offhand. If you want the Cogito to be the foundation of your enterprise, you will need more than intuition.

Sure, @Corvus has it wrong. That doesn't make you right.

The catchphrase is not a syllogism, the complete argument is. — Lionino

What you call "the complete argument" is obviously circular. Hardly convincing.

...the complete argument is:
Thinking → existing
I think
Therefore I exist — Lionino

You assume your conclusion in the first line of your argument.

You yourself said earlier "you must start somewhere". A start is a foundation, if you agree that we need a solid one, you side with Descartes, if you are of the side that we don't need a solid one, you are a skeptic and a pragmatist. Pick your poison. — Lionino

You are playing on "solid" here, on the he misapprehension that we can only know stuff if we are certain of it, if our belief is indubitable.

If you want the Cogito to be the foundation of your enterprise, you will need more than intuition. — Banno

Which part of the reasoning process do you personally think is 'just an intuition'?

Can you show that the Cogito is a valid inference? Can you set out it's logical structure, so that we can see why we ought accept it's conclusion, if we accept it's assumption?

And if not, why should we accept it?

For one to think, one must exist. I think. Therefore, I exist.

The conclusion here of course isn't "Flannel Jesus exists", the "I" is a variable for the reader to place his own identity into it. This was a confusion that Corvus had - he would read the above and think I'm trying to prove to him that I exist. That's decidedly *not* the point of it - I'm sure you already know this, but I'm just making extra-sure. The conclusion I would want you to draw from it is not that "Flannel Jesus exists", but rather that Banno exists - and if Corvus was reading this, the conclusion I'd want him to draw is that Corvus exists. The "I" is a stand-in for whoever is doing the thinking - you do your own thinking, so you put your own identity into "I think therefore I am".

I've gone on about that for long enough, considering you probably already knew that, so that being said...

Would you please just honestly tell me, do you personally disagree with (a) your own existence, and/or (b) the idea that you wouldn't be able to think if you didn't exist? If you disagree with a and/or b, could you please try to clarify why?

Is it a valid inference, on which we must all agree, or is it an intuition, a mere hunch or impression? — Banno

Has anyone ever wondered if they might not actually exist successfully?

A good solid “wait a minute…am I?”

You doubt everything first, see if you can. No matter how far you get - total blackness, sensory deprivation, mind in a vat, lose the vat, lose the mind - if you find yourself no longer thinking, no longer doubting, or breathing, or you can’t find yourself anywhere anymore, you may have gone too far.

I have a hunch no one can get that far, because “I am” is either riding shotgun, or is the bus.

(1) If I think, then I exist.
(2) I think.
(3) Therefore, I exist.

Premise one is not explicitly stated in the cogito argument (at least I don't think it is), but surely it is implied.

The formal structure of this argument is:

(1) If p, then q.
(2) p.
(3) Therefore q.

It is a valid argument.

Or have I missed the boat on this one?

if you find yourself no longer thinking, no longer doubting, or breathing, or you can’t find yourself anywhere anymore, you may have gone too far. — Fire Ologist

Or if you talk to some meditators, you've gone exactly where you should have. Though I'd agree with you, that's probably too far (except for a select few, who would probably benefit from mental non-existence - people for whom life is just complete needless suffering, for example, extreme chronic pain sufferers perhaps)

For one to think, one must exist. — flannel jesus

Why?

p⊃q is not a valid argument.

Move past attacking Corvus ad nauseam, we agree that he does not show the Cogito to be invalid. But can you show it to be valid?

Or is it something else? If so, what?

See

(1) If I think, then I exist. — NotAristotle

Isn't that exactly what it was you were trying to prove, NotAristotle?

Would you please just honestly tell me, do you personally disagree with (a) your own existence, and/or (b) the idea that you wouldn't be able to think if you didn't exist? If you disagree with a and/or b, could you please try to clarify why?

...the idea that you wouldn't be able to think if you didn't exist? — flannel jesus

Notice the presumption in that? Consider again Russell's objection - There is thinking occurring, but what is the "I"?

The other reading, which you might be groping towards, is to take the Cogito as a definition of "I"; that "I" am the thing that thinks - well, strictly, doubts.

You insist I answer your question when you have not answered mine - inference or intuition? Admit it is an intuition, not an inference.

All, can you see that the Cogito does not provide the certainty you crave?

"I exist" is an inference. "I must exist in order to think" might be an intuition, I'm not sure. I'm asking you what you think because I think you might be able to help me figure it out. I don't think you can help me without honestly expressing your own thoughts though, so that's what I want from you.

A better account than others have provided.

Can you doubt that you are now reading my reply?

Point being, at the level you want to work, there are quite a few things besides the Cogito that are evident.

I've set out my view. The project here, to find something indubitable, is the source of the problem. Just as we can require reasons to believe, we can require reasons to doubt.

Or not.

"I exist" is an inference. — flannel jesus

Ok, so from what is it to be inferred? And if the answer is "I think", then how is the inference valid?

Consider this: we know things despite not being "100% certain".

Can you doubt that you are now reading my reply?

Point being, at the level you want to work, there are quite a few things besides the Cogito that are evident. — Banno

Yes, I can doubt everything except that I am doubting (which already includes that I am, which is the point of cogito).

What do you mean “at the level I want to work”?

All, can you see that the Cogito does not provide the certainty you crave? — Banno

I can see that's a loaded question. :wink:

Here is a more formal statement of an argument:

(1) if not (p then q), then (if not-q then possibly p).
(2) not-(p then q).
(3) Therefore, If not-q then possibly p.

Can we all agree with the first conditional, or would someone object to it (and if so what is the objection).

Yes, I can doubt everything except that I am doubting (which already includes that I am, which is the point of cogito). — Fire Ologist

Well, it seems from the length of this thread, that one can doubt that, too.

Mind your p's and q's. What are they?

It's a secret. So what do you say, does that argument look agreeable?

I just mean formally speaking, let's not worry about what our premises are for now.

:roll:

It is valid.

I do not know what your emoji means.

It means "get on with it".

Splendid!

Now consider this argument:

If not (if I think, then I exist), then (if I don't exist, then possibly I think).
Not (If I think, then I exist).
Therefore, if I don't exist, then possibly I think.

Would you endorse the above conclusion, or reject it? I mean just the last line, does it seem agreeable to you?

if I don't exist, then possibly I think. — NotAristotle

Is that what you wanted to show? That's not the cogito.