Srap Tasmaner wrote the following last year:

" The barber (B), a philosopher (T) who doesn't shave himself, and a mathematician (M) who does.

We have all and only men who shave all and only men who don't shave themselves.

1. M is never a member of R because he shaves a man who shaves himself.
2. P can't be a member either because he doesn't shave himself, so he'd have to shave himself to be a member, but he doesn't.
3. What about B? He would have to shave P and not M. No problem. If he shaves himself, he'd be out, like M, but if he doesn't, he'd be out like P. So B can't be a member no matter what he does.

So R = { }. No one shaves all and only men who do not shave themselves, therefore the barber does not shave all and only men who do not shave themselves. The three cases are exhaustive, in fact: no one can be a member of R whether they shave themselves or not.
— Srap Tasmaner"

What is your analysis? If logic breaks down here, does it break down in your argument by implication?
Thanks

Descartes tried and he ended up using the ontological argument to get out — Gregory

Well, I don't know if I should argue with you about that, since that would get us slightly off-topic, but I'll only say this:

It seems to me like Descartes was inconsistent when he thought that that argument was a certain proof of God's existence, because that seems incompatible with his previous attitude of doubting everything.

First, because his argument against the Evil Demon deceiving us based on the fact that God exists and is good, begs the question: He already assumes that he is not deceived by the Demon when he starts and ends to reason about the existence of God, and assumes that his argument proving God's existence cannot be flawed in any way. It seems odd that he doubted that 2+2=4 or that a square has 4 sides, but not that.

Then there is this other inconsistency:

(Descartes') reasoning that we can trust our cognitive abilities on the basis of the truthfulness of God is far from convincing, not only because his arguments for God's existence are flawed, but because he assumed that the reliability of our perception and our logical instruments was based on God's moral perfection and the resulting certainty that He cannot deceive us. But God's goodness and omniscience do not necessarily mean that he can never mislead us. It cannot be excluded a priori that the truth, let alone the whole truth, is harmful to imperfect creatures and that in some cases it is good for us to be misinformed. In any case, there is nothing obvious in the assumption that truth cannot conflict with other goods; this would have to be demonstrated separately.

Leszek Kolakowski

I was just trying to emphasize the ideas and things I was talking about to avoid confusion, and thought it unnecessary to use the quote function for that.

But ok, I'll stop that.

I don't know that anyone can follow through with all doubts. Descartes tried and his doubts ripped through math and empiricism but had to fall short, for some reason, before his two ontological arguments for God. Others will be rationally capable of doubting God (in order to test the strength of rational faith) but will stop short of doubting math. Everyone might be different and I don't know if your argument just works for you but is incapable of working in other minds, keep in mind that other people have different logical aparatuses and that you argument may never work for some people, and not to their fault. Why not give Descartes 5 meditations another read today? They are fun and were the first complete work on first philosophy I read. His "Replies to Objections" are fascinating too

I don't know if your argument just works for you but is incapable of working in other minds, keep in mind that other people have different logical aparatuses and that you argument may never work for some people, and not to their fault. — Gregory

You sound kind of like a relativist here, since you say people «have different logical aparatuses», which sounds a lot like Protagoras' doctrine that «each man is the measure of all things».

I don't mind, but is that really what you are saying?

I thought most people just took things like the Law of Contradiction or the Law of the Excluded Middle for granted, just as they take it for granted that they are not constantly deceived. Wouldn't you say it's possible that each logical apparatus can at least have something in common with the others?

Take relativity for example, instead of relativism. There is a Meta sense in which to people really talk to each other face to face and have "a moment". But simultaneity is rejected in relativity as in Kantianism. Balancing both truths is important and the bottom line is people will always disagree with each other. As I experience life and the world, I am not much concerned with finding something abstract which everyone must agree on. Conversations on this forum are just digital "face to face" discussions designed to stimulate thought. If you contradict something my heart knows is wrong, I will contradict you

Balancing both truths is important and the bottom line is people will always disagree with each other. — Gregory

I quite agree.

If you contradict something my heart knows is wrong, I will contradict you — Gregory

Fair enough.

If you and I were in identical mental states and given identical arguments, we would come up with the same results if we chose to follow the truth of logic. However minds right from the start are infinitely complex so you can never be sure where my mind, heart, or soul is. Catholicism teaches you cannot even infallibly know the state of your own soul (council of Trent) let alone someone else's (pius x in pascendi), and in common usage the mind is the soul. These are certain things in Catholicism I think are correct although I don't go to church

What is your analysis? If logic breaks down here, does it break down in your argument by implication? — Gregory

If I were to look at that here that would get us off topic (specially since after reading your thread it's still unclear to me how the argument is related to the barber paradox).

Is it possible for me to send you a private message in this site, or should I post in that old thread?

Post your thoughts on that thread. I thought that it indicated that proving anything a priori from logic alone is futile, but I may be wrong