Its all about the context of the question asked. "Is existence real" is a legitimate question. Because nobody can prove that to be an absolute truth if it were to be false everything built on that presupposition would also be false in the realm of "what is real/true".

This is why I consider medical depression a "existential question". Half baked thought but I consider the two tied in some manner.

Again, I'm not asserting my statements/positions as definitely true. — 83nt0n

If you do not believe that anything you say is definitely true, including your assertions about your own beliefs, then how on earth is anyone supposed to have a meaningful conversation with you?

But the axioms that classical deductive logic employs are unsupported. — 83nt0n

There you go again, making an assertion. You need to stop doing that if you want to convince people that you are a genuine skeptic, but I guess you have no way of knowing whether you want to do that. Anyway, I suggest looking up the definition of "axiom."

Again, this is not an assertion. — 83nt0n

Now you are asserting that an assertion is not an assertion--self-defeating, just like I said.

This is how it seems to me. — 83nt0n

Asserting how it seems is still an assertion.

I have to utilize appearances, as I have nothing else to allow me to hold a conversation. — 83nt0n

See, you just used modus ponens. "If I have nothing else to allow me to hold a conversation, then I have to utilize appearances. I have nothing else to allow me to hold a conversation. Therefore, I have to utilize appearances."

It could be that someone does have knowledge, but as of yet I haven't found any. — 83nt0n

We have exchanged several posts now, all utilizing the English language. Unless you wish to claim that we have been throwing gibberish at each other, clearly you and I both have knowledge of the English language.

Sorry, I still have no idea what you are talking about or how it relates to my exchange with @83nt0n.

how on earth is anyone supposed to have a meaningful conversation with you? — aletheist

As I explained previously, I only say how things appear to me. This allows for a conversation.

Anyway, I suggest looking up the definition of "axiom." — aletheist

axiom: a statement or proposition which is regarded as being established, accepted, or self-evidently true
I could assert that "my big toe is purple" is an axiom, but I need to demonstrate that it is true. Same with other axioms. You should look into Agrippa's Trilemma a bit more.

Now you are asserting that an assertion is not an assertion--self-defeating, just like I said. — aletheist

I did not say that as an assertion. And I AM NOT asserting this either.

See, you just used modus ponens. "If I have nothing else to allow me to hold a conversation, then I have to utilize appearances. I have nothing else to allow me to hold a conversation. Therefore, I have to utilize appearances." — aletheist

Again, I may not be able to help but use deductive logic, but how does my inability to be a complete skeptic have any bearing on skepticism as a position?

We have exchanged several posts now, all utilizing the English language. Unless you wish to claim that we have been throwing gibberish at each other, clearly you and I both have knowledge of the English language. — aletheist

This might not be the same as propositional knowledge, which is the knowledge that I am talking about.

If you're saying that because I use the English language, I know how it works, this seems to be flawed reasoning. Just because someone uses their brain doesn't mean they know how it works.

Overall, no offense, but I don't think you understand my position at all. Check out the Youtube channel carneades.org (he's better at explaining things than I am).

Well I can't force your eyes to see what's in my mind and vice versa. Why don't you give me some direction where the breakdown in communication happened?

As I explained previously, I only say how things appear to me. — 83nt0n

Another assertion.

I could assert that "my big toe is purple" is an axiom, but I need to demonstrate that it is true. — 83nt0n

No, you do not. Read the definition of "axiom" that you quoted again.

I did not say that as an assertion. And I AM NOT asserting this either. — 83nt0n

Two more assertions.

how does my inability to be a complete skeptic have any bearing on skepticism as a position? — 83nt0n

It is not so much your individual inability as the fact that no one can be a complete skeptic--again, such a position is self-defeating--so it then becomes a matter of which beliefs you adopt, just like anyone else.

This might not be the same as propositional knowledge, which is the knowledge that I am talking about. — 83nt0n

You and I are competent users of the English language. This is a true proposition that we both justifiably believe. Therefore, we both have propositional knowledge.

Overall, no offense, but I don't think you understand my position at all. — 83nt0n

Right back at you.

Why don't you give me some direction where the breakdown in communication happened? — ISeeIDoIAm

When you started posting.

Well tbh I'm not sure I want to have the same conversation twice. Unless you give me something to work with I'm willing to let bygones be bygones.

No, you do not. Read the definition of "axiom" that you quoted again. — aletheist

You are right; my example is not a good one. But the way I see it, no beliefs/truths are self-evident.

It is not so much your individual inability as the fact that no one can be a complete skeptic--again, such a position is self-defeating--so it then becomes a matter of which beliefs you adopt, just like anyone else. — aletheist

This is probably true, but adopting beliefs would not consist of knowledge, which is what I want.

Right back at you. — aletheist

All of your objections to my position are very common. I understand your objections, but they do not hold up. I think I am going to stop arguing with you, so I advise that you watch carneades.org playlist "In defense of skepticism".

I'd say we're using simple questioning to argue that deductive logic is flawed. However, if deductive logic shows that deductive logic is flawed, then deductive logic is flawed. — 83nt0n

Hypothetically if deductive logic was flawed, what would you replace it with? The most you could say against deductive logic is that out of the trillions variables that reality deals with, not all those variables are known to apply to the overall equation. In other words deductive logic isn't flawed, however people only have so much information at their disposal.

Its a clever story, but if that story was instead written as a mathematical proof we could all get to the bottom of it real quick. Like i said before deductive reasoning only fails when not all variables or not all important variables are known to answer the question.

Perhaps next time you should show the story like you did but then place the mathematical proof next to it. Otherwise you are only going to fool uninformed people, which you may have succeeded in doing that.

Also you [@Nagase] seem to assume that if a rule goes from true beliefs to true beliefs, it is justified. — 83nt0n

Agreed.

Once again, this is using modus ponens to prove modus ponens. — 83nt0n

I disagree. It might just be recognising soundness as a self-evident virtue. Another modus ponens (aside from the one being justified) needn't be involved. You were just on a roll with that objection, no? It is the tortoise's expected refrain, true, but the tortoise doesn't talk about this combination, wherein the student accepts A, B and Z (from true to true) but not C (the rule). The tortoise invites us to justify Z on the basis of A and B, and then of course he claims to need C (and then D etc).

I only mention this in case it connects the tortoise's problem to the alleged 'scandal' of deduction: of its telling us no more than we already knew; of soundness being an empty (as well as self-evident) virtue. If Z does indeed follow from A and B as C claims, then C goes without saying. So much then for,

“Whatever Logic is good enough to tell me is worth writing down,” said the
Tortoise.

Nonlinear reasoning does not avoid circular reasoning; it argues that, in some cases, it is both unavoidable and not vicious (or, perhaps, more positively, indeed virtuous). That is Quine's stance: we always start in the middle of things, so to speak, and there is no problem in using our background knowledge to understand how we came to have that knowledge in the first place. The point is that, once we realize that our knowledge is not linearly arranged, but rather forms an intricate web, we give up the search for foundations (so that the aim of epistemology is not to secure knowledge---i.e. it is precisely not to argue against the skeptic), and rather try simply to further the knowledge we already have.