Well, no, that's not how a reductio works.

It's in the nature of reductio arguments to assume what is in contention and then derive a contradiction from that assumption. that's what I have done here. Assume Bart is right, and noncontradiction is not necessary. Then in some possible word, contradictions ensue. Hence, the assumption is false. — Banno

t's in the nature of reductio arguments to assume what is in contention and then derive a contradiction from that assumption. that's what I have done here. Assume Bart is right, and noncontradiction is not necessary. Then in some possible word, contradictions ensue. Hence, the assumption is false. — Banno

I don't deny that there is a possible world in which contradictions are true (whatever a 'possible world' is - I have no idea). I claim that in the actual world contradictions are not true.

Show me how I am contradicting myself.

I don't deny that there is a possible world in which contradictions are true (whatever a 'possible world' is - I have no idea). I claim that in the actual world contradictions are not true.

Show me how I am contradicting myself. — Bartricks

You are in the actual world claiming there is an instance contradictions are true. game set match

I claim that in the actual world contradictions are not true... Show me how I am contradicting myself. — Bartricks

Bartricks claims that there are contradictions in the word. Hence he claims that for some proposition A, both A and ~A are true.

If A and ~A are true, then any proposition is true.

If anything is true, then "Bartricks does not claim that there are contradictions in the word" is true.

Hence, Bartricks claims that there are contradictions in the word, and Bartricks does not claim that there are contradictions in the word.

Which was to be proved.

Edit: Added link to wiki article on explosion.

by way of justification for the line:

If A and ~A are true, then any proposition is true.

Of course it is open to Bartricks to deny this, too; but we are quickly running out of anything that might work as a principle to decide what is reasonable and what isn't. Hence my previously stated opinion that it is not worth arguing with someone who denies the law of noncontradiction.

Yep. Our resident expert on rationality has a problem.

I think he's a robot. I don't mean that as an insult.

You are in the actual world claiming there is an instance contradictions are true. game set match — Cheshire

Er, no. I am in the actual world claiming that in the actual world no true proposition is also false.

Just as I am in the actual world claiming that there are no unicorns in the actual world

I claim that it is 'possible' - metaphysically possible, not epistemically possible - for true propositions also to be false. That does not mean that I am asserting that any actually true proposition is also false.

It is also metaphysically possible for unicorns to exist. That doesn't mean I think unicorns exist or that I ride to work on one.

So, not 'match', rather you've tried to return my serve using your face as a racket and now you are wondering why all your teeth are on the grass and not in your mouth.

What? More squiggles and squoggles. You love your latin and your squoggles, don't you?

Bartricks claims that there are contradictions in the word. Hence he claims that for some proposition A, both A and ~A are true. — Banno

No, I claim that there are no true contradictions in the actual world. I mean, I've said that now about a 100 times. Maybe you should learn English 'before' you start squiggling and squoggling.

Now, again, Bartricks claims that if a proposition is true, it is not also false. I think that's true. True. True . True. True. Is there a squiggle or a squoggle for true? Maybe it'll sink in if I squoggle it. How about this - $. Let $ mean 'true'. Now let % mean a proposition. Now let ! mean not. And let ? mean false. And * can mean Bartricks.

* thinks that it is $ that if a % is $, then it is ! also ?

There - has that helped?

And if you like, we can call that claim a Bartrikium Tartidium, as I know you like Latin and that sounds a bit Latin to me.

Yes, I understand that you are claiming that the laws of logic hold in the actual world but not in other possible worlds.

I've shown how that leads to contradiction.

So to match your shifting goals, here's an alternate rendering:

Bartricks claims that there are contradictions in some possible word. Hence he claims that for some proposition A, both A and ~A are true.

If A and ~A are true, then any proposition is true.

If anything is true, then "Bartricks does not claim that there are contradictions in that possible world" is true.

Hence, Bartricks claims that there are contradictions in some possible word, and Bartricks does not claim that there are contradictions in that possible word.

Which was to be proved — Banno

Yes, I understand that you are claiming that the laws of logic hold in the actual world but not in other possible worlds. — Banno

Good. But....

Bartricks claims that there are contradictions in some possible word. Hence he claims that for some proposition A, both A and ~A are true. — Banno

Squiggles and squoggles. Let's get rid of them, shall we. So, you have attributed to me the view that I think that for some proposition A, A is both true and false. Yes? That's not my view.

My view is that any proposition that is true in the actual world, is not also false.

Look, you might as well give up - you need a bridge from what I say about possible worlds to this world. But you don't have one. Necessity is what'd give you it. But necessity is what's at issue.

You're not going to be able to get from contradictions being true in a possible world, to contradictions being true here. Not without necessity's help. And necessity isn't there to help you. The instant you try and get necessity to help you, the game is up - you've begged the question.

Again, you need to show that I've contradicted myself and you're just not going to be able to do that. All you're doing is showing that I am contradicting you. But, thank God, I am not you.

Squiggles and squoggles. Let's get rid of them, shall we. — Bartricks

Well, no, since they are part and parcel of the logic you claim to understand, and they permit us to see the structure of the arguments more clearly.

you have attributed to me the view that I think that for some proposition A, A is both true and false. Yes? — Bartricks

No, I have demonstrated that the view that for some proposition A, A is both true and false, is a consequence of your view that the law of noncontradiction does not apply in some possible worlds. Reject noncontradiction in any possible world, and you reject it for every possible world.

Look, you might as well give up — Bartricks

On this we agree.

Oh, what an opportunity that would be. Yes, I'd love to discuss dialethism with him. — Banno

So, just to be clear: you think it pointless to engage in philosophical discussion with a philosopher who thinks the law of non-contradiction is true, but you'd love to engage in philosophical discussion with a philosopher who thinks it is false? Peculiar.

I'm sure he would make an excellent argument for dialetheism. That's what's missing here

Squiggles and squoggles. Let's get rid of them, shall we.
— Bartricks

Well, no, since they are part and parcel of the logic you claim to understand, and they permit us to see the structure of the arguments more clearly. — Banno

No, they make it less clear for I don't know what they mean. YOu might as well express yourself in German. If you genuinely wanted to be clear, you wouldn't use the symbols. Now, once more: I don't know what they mean. Use English.

No, I have demonstrated that the view that for some proposition A, A is both true and false, is a consequence of your view that the law of noncontradiction does not apply in some possible worlds. Reject noncontradiction in any possible world, and you reject it for every possible world. — Banno

No, how does that follow? That's no different from saying that if I think unicorns can exist, they do. That is, that if I accept there is a possible world in which they exist, then I must accept they exist in all possible worlds. Er, no.

I think there is a possible world (whatever one of those is) in which the law of non-contradiction is false. It doesn't follow that it is false in all possible worlds. How does that follow?? It just plain doesn't.

I'm sure he would make an excellent argument for dialetheism. That's what's missing here — Banno

Why do you think that? That is, why do you think he'd make an excellent argument for it?

And of course it is missing here - I am not arguing that the law of non-contradiction is actually false, but that it is true, just contingently. Or rather, that there is no contradiction involved in holding that view. (I can argue for it too - excellently - but that would be off topic).

No, they make it less clear for I don't know what they mean. — Bartricks

Well, here's the odd thing; those symbols are pretty standard, and anyone who has taken the trouble to study logic will be familiar with them. But also, there is an audience to these proceedings,a nd I am writing for the as well as for you.

No, how does that follow? — Bartricks

I've presented the argument three - or is it four - times. Its just applying the so-called principle of explosion to modality.

I think there is a possible world (whatever one of those is) in which the law of non-contradiction is false. It doesn't follow that it is false in all possible worlds. How does that follow?? It just plain doesn't. — Bartricks

You are very fond of demanding that folk address your argument. I have presented an argument showing that it does. Please address it.

Because he knows his stuff. For example, he can read and write the Squiggles and squoggles.

I am not arguing that the law of non-contradiction is actually false, but that it is true, just contingently. Or rather, that there is no contradiction involved in holding that view. — Bartricks

So you are arguing that there is no contradiction involved in holding the view that non-contradiction is false.

You are arguing that there is no contradiction involved in holding the view that in some possible world there are contradictions.

Well, here's the odd thing; those symbols are pretty standard, and anyone who has taken the trouble to study logic will be familiar with them. But also, there is an audience to these proceedings,a nd I am writing for the as well as for you. — Banno

Well, I have told you several times that I don't understand them. If you just expressed yourself in english rather than symbols it'd be clearer to us all that your arguments don't stack up.

I've presented the argument three - or is it four - times. Its just applying the so-called principle of explosion to modality. — Banno

Yes, and I keep asking you to remove the symbols - they come in at the crucial point and I think that's no accident. I think you can't show me to be committing a contradiction, because I claim not that the law of non-contradiction is false, but that it is contingently true. And to get from 'there is a possible world in which it is false' to 'it is actually false' you'd need to help yourself to the notion of necessity, as I keep saying. Perhaps you think that if there is a symbol for necessity, then you're off the hook. No. I will just keep pressing you to express yourself in English until it becomes clear. You are arguing in a circle. As ever.

You are very fond of demanding that folk address your argument. I have presented an argument showing that it does. Please address it. — Banno

You presented it in German, as far as I am concerned. Express it in English.

Because he knows his stuff. For example, he can read the Squiggles and squoggles. — Banno

That's not what 'knowing your stuff' involves. Plato wouldn't have had a clue about the squiggles and squoggles. I think you don't know your stuff and you are hiding behind squiggles and squoggles. Come out from behind the squiggles and squoggles, Banno, if you dare.

So you are arguing that there is no contradiction involved in holding the view that non-contradiction is false. — Banno

Oh dear Banno. Don't you read English, Banno? I think the law of non-contradiction is true. Remember?

If I thought the law of non-contradiction was false, then of course I'd be affirming a contradiction, for I would be saying that some true propositions are also false in the actual world.

But that's not what I am saying. I am saying that the law of non-contradiction is true. It is just not necessarily true, that's all.

When is the penny going to drop? I wonder....

they come in at the crucial point and I think that's no accident. — Bartricks

Logicians using secret symbols to hide their dark deeds.

to get from 'there is a possible world in which it is false' to 'it is actually false' you'd need to help yourself to the notion of necessity, — Bartricks

You do understand that "possibly P" is the same as "not necessarily not P" I hope - so if I am helping myself, it's because necessity is already there.

That's not what 'knowing your stuff' involves. — Bartricks

Yes, it is. Again, any one with a philosophical background ought be able to follow the simple symbols "A" and "~". Especially anyone claiming even a cursory understanding of logic.

So as it stands, you are now claiming not to understand my argument. So how can you tell I am wrong?

As for the rest, you are simply repeating yourself.

When is the penny going to drop? I wonder.... — Bartricks

As do I.

You don't have an argument, do you? I say that it is possible for the law of non contradiction to be false, and all you can do is insist that means I think it is actually false.
No, it is 'possibly' false. That doesn't mean 'false'.
And now you say that necessity is there because 'possibly false' means 'not necessarily true'. Er 'not necessarily true' is a denial of necessity's presence. That's what 'not' means.

You see, I don't know what the symbols mean, but I can reason well. You can't. That's the difference between knowing your stuff and not. I can see that there is no contradiction involved in saying that it is metaphysically possible for the law of non contradiction to be false. You don't need to know the symbol language to be able to see that. You just need to be clever (and tbh, not very).

So, once more, prove me wrong - using English words, not symbols (so no little wiggly lines Banno - I know you like them, but they just make you look silly - and no saying you already have. You haven't. No wiggles. Just words.

Do you understand the task? I am claiming that the law of non contradiction - according to which if a proposition is true, it is not also false - is true, but contingently true. You are claiming that I am contradicting myself by saying that. But so far all you keep doing is saying that again and again without showing it. And everytime you attempt to show it you just assume that it is true of necessity and not contingently. Which isn't a demonstration that I have contradicted myself, but a demonstration of poor reasoning skills on your part.

I will take any squiggle use to be an admission of defeat. And likewise for the claim that you have already done so. No squiggles. No fibs. Just English. Do it.

Why not say that in this world logic applies and in another works something beyond logic could apply, a logic that dovetails our own in a way but is not contradictory? Why insist that contradiction instead of sublation is possible? You don't know if your God experiences his contradictions as contradictions

Maybe "God", who you say can do anything, predestined that Banno be right is this discussion and you wrong. But you don't like to be contradicted and hate when others disagree with you because you throw what appear as tantrums because you think you are so smart. I don't think you're a bot but others of have claimed this already. You don't learn from other people and that is an issue of maturity

So maybe God can do everything but doesn't do any contradictions except one: to make Bartricks always wrong. Maybe "she" is out to get you

Focus on the argument and not the arguer. What I can't stand are shit arguments.
Now Banno has a shit argument. Banno thinks that if the law of non contradiction is contingently true, then it is actually false. Which is, irony of ironies, a contradiction! Banno thinks if something is contingent, then it is not contingent. An actual contradiction!
He thinks I am committing contradictions. He has no argument to show this and is himself committing a contradiction, given he thinks that if something is contingently true then it is also false. He is VERY confused, but doesn't know it. Which is the worst kind of confusion, because it is so hard to remove.

So how do you know God hasn't made it such that everyone should believe in the law of contradiction except she predestined you to not agree with it in order to convict you of a sin. God can do anything, even make this seem improbable to you as you slip towards hell. You think this world is home but God can do anything anything, make you wrong in this debate, make you evil though you don't know, anything whatsoever she wishes

Gregory, your comprehension skills seem to be somewhere between those of a rock and a newt. I think the law of non contradiction is TRUE. I have said this countless times. I think it is true,not false.

I think it is 'contingently' true. Most think it is 'necessarily' true. I understand why they do and other things being equal it is an eminently reasonable thing to believe about it, given virtually everyone's rational intuitions represent it to be. And that's very powerful apparent evidence that it is necessarily true.

But the issue here is whether, in believing the law of non contradiction to be contingently true rather than necessarily true, I am committing a contradiction. And clearly I am not.

So the law of contradiction can be set aside for us. So God can make you always wrong and me always right, you bad and me always innocent. God can do anything in our world. Maybe he make you bad last night and the rest of the world good such that you are the only bad person in existence. This is your logic not mine. Your trying to find a bubble but God can do anything so you have none

'Can' is the important word there. Yes, he 'can'. That's why there are no necessary truths, just contingent ones. God 'can' do anything.
If God exists, then there are no necessary truths. One would be affirming a contradiction if one thought otherwise.
The irony here is that though I think the law of non contradiction is contingent, I seem to be the only one concerned to obey it.