frank

Yea, well...

All he had to do is say that there aren't any cases where both premises are true, therefore it's valid.

Sounds uncomfortable.

I imagine you finally had to retire to the insane asylum. Enjoy the rocking chair.

Yes. I edited that post. It's just weird that any argument that can't have all true premises is going to be valid.

Oh. So then any argument that has no true premises is valid. That's weird.

Sure. If a statement is trivially true, it's not informative. For instance, a tautology is trivially true. The T-sentence rule is trivially true. Unde...

"Trivial" has a clear meaning in analytical philosophy.

Correct

If the antecedent in the conditional is false, then the first premise is true. Now say the second premise is true. Then the conclusion does not follow...

Sure. I would encourage you to write out in English the only case where both premises are true, and see if you think not-A makes sense as the conclusi...

Yes. In the only interpretation where both premises are true, there's no way to conclude not-A

I think you need to know what "trivially true" means.

No. It's that if A is false, the first premise is trivially true. So the argument is one in which the first premise doesn't say anything. The argument...

If I gave you a quote from a respected authority advising that if the antecedent of a conditional is false, the conditional is trivially true, would y...

If the antecedent is false, the conditional is trivially true, right?

Vacuously true. Trivially true. Correct?

Ok. If the antecedent of a conditional is false, the conditional is vacuously true. Right?

If the hypothetical of a conditional is false, the conditional is trivially true. Is this correct?

I get that you're frustrated. Thanks for hanging in there. If the hypothetical in the first premise is false, isn't the first premise trivially true? ...

Ok. So with a false premise, the conditional is true by default. That means the first premise is actually not-A, right? Wait, no, the first premise do...

I think you did swap out the first premise when you made the first A false, but not the second one. Is that wrong?

Wait a minute. If A is false, then the first premise is: If not-A, then not (not-A) You can't change one of the A's to false and not the other one. If...

The conclusion always comes out as not-A. Tones is basically swapping the first premise out with a different one by considering an "interpretation" wh...

Yea, you're right.

"A conditional statement is false if hypothesis is true and the conclusion is false.". here And if A is true, we can't have not-A as the conclusion, s...

I think Hanover was talking about the argument in the OP. It can't be valid because the first premise is necessarily false, right?

Isn't the first premise: If A, then not-A? That's what it looks like

Is it not? It's expressing a contradiction. Contradictions are necessarily false, right?

I think the first premise is necessarily false in propositional logic.

So we know the first premise is necessarily false. That means the conclusion has to be false for validity. Is the conclusion false?

But with validity, aren't we looking at what happens when all the premises are true? If a premise is necessarily false, can we still look at the argum...

But what if you say the first premise is necessarily false? It can't be true. Then what do you get?

How are you getting A as a conclusion?

I think you're treating A -> ~A as if it's hypothetically true. They're just declaring it to be necessarily false.

Yes, religion is the 'opium of the people.'. An anesthetic can support functionality when times are tough. I think that's one reason for the endurance...

Yay! Let's go take over a government building!

What are your thoughts on logical pluralism?

You're just not going to read anything about it. That's cool. :up:

The opening lines of the SEP article on logical pluralism acknowledge that the idea seems crazy at first glance, but that it becomes more plausible on...

So if you're a 2nd Century BCE Carthaginian, it's moral to sacrifice babies to Baal. What does this have to do with anything?

It's arbitrary that you want logic to capture natural language good reasoning. If I need faster than light travel, I may need an alternative to natura...

You've got the appropriate logic if it fits your purposes with regard to a specific domain.

"Correct" in that quote basically means appropriate. It has nothing to do with truth.

Majority acceptance does not signify that a moral stance is right. That's what matters.

Your posts show why it's such an emotionally charged topic. :strong:

We're done. :smile:

Since I don't know who they were or why they responded as they did, there's no way to resolve the question. What makes you think this? I'm in the midd...

Either the folks who responded that they accept correspondence theory didn't understand the question, or they interpreted "correspondence" in some cre...

I'm just telling you that your data does not represent the view in contemporary philosophy. Let's look at a specific responder and analyze exactly wha...