That such an argument is valid. I admit that when we get down to the most basic examples of proof the similarity to persuasion is less visible/arguable. But this is to steer the thread, in my eyes, from the its intended focus.

For the sake of argument, let's call tautologies proofs. How far can we go from there before the line blues twixt proof and persuasion?

I don't believe I did. I hope not.

I think it's the difference between a tool and what that tool is used for. True a proof is usually used to persuade just as a paintbrush is usually used for painting but a paintbrush is not painting.

Is there some important difference between "proof" and "a proof"?

No not you.

I'm looking at the more casual use of the word "proof." Like "here's the proof." I'm looking especially at more abstract discussion, like the one we are having about this issue right now. First philosophy/metaphysics is a good example. I feel that the detour toward geometry and tautology has been a bit misleading.

I'm looking at the more casual use of the word "proof." Like "here's the proof." I'm looking especially at more abstract discussion, like the one we are having about this issue right now. First philosophy/metaphysics is a good example. I feel that the detour toward geometry and tautology has been a bit misleading.

You seem to want to approach proof only asymptotically. You want to keep it within the same function as persuasion. Another geometric analogy but more Cartesian than Euclidean this time.

f(x) = 1/x
When x = 0, f(x) = proof

I think you'd agree that some people gain a sense of pride or certainty from an understanding of logic, but they commit the following fallacy: That just because their form of argument is sound, that means the argument itelf is or is more likely sound.

Descartes writes that his proofs of God are not meant to persuade, since he realizes that those professors at the Sorbonne for whom he composed the proofs were already persuaded that God exists. But his purpose in composing the proofs was to put the belief in God on a firm basis.

Descartes explains this in his introduction to his Meditations.

So, there you go!

I may be persuaded that Quito is the capital of Ecuador. But, just to make sure, I may look it up in the Atlas. There you go again!

Our worlds seem largely made of sentences.

I will pick out this one sentence among the others in your last post. Sentence have a grammar. Language has a grammar. Syntactic structures. These structures imposes limits upon us. The limits that proof imposes feels similar to those which are imposed by the structure of language language itself

I will pick out this one sentence among the others in your last post. Sentence have a grammar. Language has a grammar. Syntactic structures. These structures imposes limits upon us. The limits that proof imposes feels similar to those which are imposed by the structure of language language itself

Then our trust is in the structure of language and whatever brought that structure into existence. If it was because we view the world on this particular scale, we may be screwed, lol!

I understand the first line, but the second isn't clear to me. I would like to know exactly what you mean --out of curiosity, of course, not to nit-pick.

If quantum physics is more accurate than classical physics, then random events do occur and there isn't always a cause for every effect. Cause and effect is one of the most basic intuitive ideas, if that is wrong it follows that the structure of language may be wrong and all things stemming from it, like Logic.

Yeah I botched it. It was an invalid argument. Maybe I'll start a thread in philosophy 101 about this and so I did

http://www.philosophyforum.com/philosophy-forums/philosophy-101/7679-what-difference-between-fallacious-arguement-invalid-arguement.html

If I say that A implies B and B implies C therefore A implies C is a valid argument then what am I trying to persuade you of? A implies C? What is A? what is C?

This is an example of a proof that is not used to persuade. The point is that this is still an argument but we have no idea what A B and C are. I'm trying to isolate proof from persuasion. I don't know if succeeded.

(Yikes Zetherin edited your post. Makes me think you said something nasty.)

What invalid argument? In any case all invalid arguments are fallacious arguments, so I still don't see what you are driving at. Capital letters, in logical schemata are stand-ins for propositions. Essentially abbreviations. All you have to do is to replace te letters with the propositions they stand in for. I have given examples of two arguments whose purpose was not to persuade.

And I responded to those two arguments.

I'm fairly sure he knows that capital letters are stand-ins. What I think he means is you still have to decide if those propositions are true meaning the argument is not sound just because its form is considered valid...

(Yikes Zetherin edited your post. Makes me think you said something nasty.)

I said truth is a property of sentences, not that truths are properties of sentences, but I think you know what I mean. Are you seriously asking if the Milky Way, to me, is the property of a sentence?

Yes, because you seemed to disagree that truths exist independent of the mind. Wasn't that the point?

Truths that exist independent of the mind. Got any examples?

Countless.

It is true that trees exist. It is true that my table is made of glass. It is true that the chemical composition of water is H2O. It is true that the planet Earth exists. It is true that most birds can fly. Etc, etc.

You really don't believe reality exists outside of the mind? Most reasonable scientists agree that the Earth was here billions of years before any minds were. So, I'm curious as to how you would explain truths only exist dependent on the mind.