I believe this thing is on my right side.
I then have a reason to believe that same thing is on my left side.
It is not true that I must now doubt the thing is on my right side, although I might.
It is true I cannot say I know the thing is on my right or on my left.

Descartes 101: that which can NOT be doubted, must be true. You are saying for that which can be doubted, its negation must be true, which does not hold.

Kant 101: no belief is ever sufficient for knowledge. You have no logical authority to claim affirmative or negative knowledge when given only reasons or no reasons to believe. So in effect, under the given conditions, you are correct in saying you cannot claim to know you are not a fool, but you would be equally correct in claiming you cannot know you are.

A brain in a vat is a scenario that is, thank you for reminding me, simply an upgrade of Descartes' deus deceptor thought experiment. It's aim is global, total, and untrestrained skpeticism which, in other words, implies nothing, absolutely nothing about our perception is reliable. So, the belief the brain in a vat = the brain in the skull, insightful though it may be, is founded on perceptions (seeing our own brains in skulls) that the brain in a vat invalidates. In legal terms, you're trying to make your case with the aid of an unreliable witness. Case closed! Court adjourned!

you're trying to make your case with the aid of an unreliable witness. — TheMadFool

No, I'm saying that it makes no difference from the stand point of the witness. And you are the witness, not the judge.

No, I'm saying that it makes no difference from the stand point of the witness. And you are the witness, not the judge. — Olivier5

A brain in a vat means our senses (the witness) can't be trusted. A brain in a skull = a brain in a vat means our senses can be trusted. You do the math.

Alright then, what is the situation your end? Are you a BiV or a BiS?

Alright then, what is the situation your end? Are you a BiV or a BiS? — Olivier5

I don't know. That's the point!

So it makes no discernable difference from your standpoint...

Oh sorry! Didn't read your question properly. My bad. Firstly, I could be a brain in a vat and ergo, whatever I perceive could be an illusion including the perception that I'm a brain in a skull!

I believe this thing is on my right side.
I then have a reason to believe that same thing is on my left side.
It is not true that I must now doubt the thing is on my right side, although I might.
It is true I cannot say I know the thing is on my right or on my left. — Mww

I agree with your reasoning.
But next time please add a quote of my comment so that I can know what you are referring exactly to! (As I do myself here.)

Descartes 101: that which can NOT be doubted, must be true. You are saying for that which can be doubted, its negation must be true, which does not hold. — Mww

I don't agree with "that which can NOT be doubted, must be true". First of all, it cannot be doubted by whom? So I will assume that it is me who cannot doubt it. So, if you say to me that you live in Hawaii, I cannot doubt either that you are telling the truth or you are lying. I have no evidence for either case. So, I certainly can't say that it is true!

(I don't quite understand the remaining of the quote you brought up. It looks like it is a continuation of Descartes' quote but it doesn't make much sense ...)

Kant 101: no belief is ever sufficient for knowledge. You have no logical authority to claim affirmative or negative knowledge when given only reasons or no reasons to believe. So in effect, under the given conditions, you are correct in saying you cannot claim to know you are not a fool, but you would be equally correct in claiming you cannot know you are. — Mww

1) Re "No belief is ever sufficient for knowledge": I agree.
2) Re "You have no logical authority to claim affirmative or negative knowledge when given only reasons or no reasons to believe.": OK
3) Re "So in effect, under the given conditions, you are correct in saying you cannot claim to know you are not a fool, but you would be equally correct in claiming you cannot know you are.": Again I can't connect this to Kant's quote ...

Please try to differentiate (using quotation marks, italics, etc.) a third person's quote from yours! Otherwise, you only create confusion and your thoughts seem dispersed!

I am aware of the facility of quotation marks. If I didn’t use them, I didn’t quote anybody.

Descartes/Kant 101 merely indicates a synopsis relevant to the topic.
—————

if you say to me that you live in Hawaii, I cannot doubt either that you are telling the truth or you are lying. I have no evidence for either case. So, I certainly can't say that it is true! — Alkis Piskas

You cannot doubt I said I live in Hawaii, so you can say it is true I said it.
You cannot doubt I am telling the truth or I am lying, so you can say it is true I am telling the truth or I am lying.
You can doubt that I live in Hawaii, so, yes, agreed, you cannot say it is true that I do. You also cannot say it is true I do not.
—————

By finding my reasoning agreeable, did it add to, or change, yours?

I am aware of the facility of quotation marks. If I didn’t use them, I didn’t quote anybody. — Mww

OK.

Descartes/Kant 101 merely indicates a synopsis relevant to the topic. — Mww

OK.

You cannot doubt I said I live in Hawaii, so you can say it is true I said it. — Mww

This is shifting from the content, meaning of the message to pronouncing the words of the message. I didn't say I cannot doubt that you said, pronounced those words. I said that I cannot doubt that you are telling the truth (or lying), namely that you are indeed living there. Please read my statement again. So this argument of yours is evidently irrelevant to what I said, which I believe was very simple and clear.. I don't know if this "switch" is done on purpose (e.g. as a form of avoiding my statement) or not. But the discussion from this point and on is useless for me. I hope you can see that.

the discussion from this point and on is useless for me. I hope you can see that. — Alkis Piskas

Saw it from the beginning.

Have a good day.