We haven't left @Hanover any space to back down without loosing face. Bit of a shame. It is astonishing that a third of those who could be bothered to vote got the answer wrong. I guess that tells us about the clientele.

They don't say otherwise. But they do not specifically rule out any substitution, including ~A for B.

Find one that does so, and you will have support for your claim.

Otherwise, the rule is that any formula can be substituted for A and B, including ~A.

And this is quite basic stuff. So from Open Logic:

A rule of inference is a conditional statement that gives a sufficient condi-
tion for a sentence in a derivation to be justified. Modus ponens is one very common such rule: it says that if φ and φ →ψ are already justified, then ψ is justified. This means that a line in a derivation containing the sentence ψ is justified, provided that both φ and φ →ψ (for some sentence φ) appear in the derivation before ψ. — Open Logic p.120

Nothing says that we may not substitute A for φ and ~A for ψ. Hence, we may. Indeed, that's kinda the point.

But this is trivial stuff! Why don't you already know this?

is clearly mistaken. As is ChatGPT.

More evidence of ChatGPT's incompetence.

And in composing a post about it, cleverly constructing a paradox. Nice.

One-third of folk here think the argument invalid. Odd.

Reference?

Yes, I'd enjoy being able to interrogate the data, although the sample size is a bit small.

A similar survey could be done here using SurveyMonkey or some other.

Good question. I don't see a question in the survey that addressed this.

After a bit more searching, there was also this:

Philosophers who reject god seem more willing to reject classical logic. Not unexpected, perhaps.

But the view that there are multiple correct logics or none wouldn't require act of faith? — Count Timothy von Icarus

Not at all.

Despite being accused of engaging in a "polemic" by , I continue to think the issue both interesting and open:

Now it seems to me that Pluralism is the better of these options, but the devil is in the detail, and the discussion is on-going. — Banno

Do you think that the discussion is closed?

↪@Leontiskos ↪Banno To what extent does your disagreement on this involve, perhaps, one being a conservative and the other liberal? — Tom Storm

A curiosity I came across in the Philpapers survey. The analysis examines correlations with other questions, most of which are to do with anti-realism and contradictions and such, where the correlations seem related. But then there was this:


There is a correlation between philosophers who reject abortion and accept only classical logic. What to make of that?

What should stand out in this discussion is that if there is one true logic, one true consequence relation. or definition of "correct logic", or a logic that can pares all arguments made in a natural language and allow us to determine their validity, or whatever monism is chosen, then it ought be possible to set it out.

But that has not been done.

So it remains that logical monism is an act of faith rather than a conclusion.

The discussion of monism, pluralism and even nihilism is ongoing, not settled.

@Count Timothy von Icarus
Providing links or references to sources and quotes, and linking mentions, are basic courtesies.

https://www.reddit.com/r/askphilosophy/comments/1ggtpw0/what_is_a_correct_logic_re_monismpluralismnihilism/

https://philosophy.stackexchange.com/questions/118553/what-is-a-correct-logic-re-the-logical-monism-pluralism-nihilism-debate

...suspicion being that all arguments for a logic must beg the question the only way to evaluate a logic is to develop and utilize it in some fashion. — Moliere

Well, validity is decided by giving a logic an interpretation. So that's pretty much correct.

Why are we having this discussion? Do you have anything to say that is to do with the topic?

Well no, — Count Timothy von Icarus

Well, yes. "The notion of A correct logic" - singular.

Just to be clear, for other folk, Tim's question is loaded precisely becasue the notion that there is a "correct logic" for which a definition might be provided is exactly what is denied by both logical pluralism and nihilism.

I doubt that a suitable definition of "correct logic" can be provided. Therefore I will refrain from providing one.

If Tim wishes, he may present one for our inspection.

Ok, so you cannot define logical monism or pluralism. — Count Timothy von Icarus

From my OP

Logical laws are supposed to work in every case. Modus Tollens, non-contradiction, identity - these work in any and all cases. A logical nihilist will reject this.


To be a law of logic, a principle must hold in complete generality
No principle holds in complete generality
____________________
There are no laws of logic.
— Gillian Russell

There are two ways to deal with this argument.

A logical monist will take the option of rejecting the conclusion, and also the second premise. For them the laws of logic hold with complete generality.

A logical pluralist will reject the conclusion and the first premise. For them laws of logic apply to discreet languages within logic, not to the whole of language. Classical logic, for example, is that part of language in which propositions have only two values, true or false. Other paraconsistent and paracomplete logics might be applied elsewhere. — Banno

Don't be a goose.

I'm asking you to show you have a basic understanding of the topic. — Count Timothy von Icarus

As things stand, I doubt you have the capacity to tell who has a " basic understanding of the topic".

You are trying to play "gotcha", but you've fumbled the ball.

:lol:

A rough outline of a direction in which a discussion will go does not amount to a definition.

In summary, in a discussion of logic, you are demanding I define a term that is not defined formally, for something that I doubt exists, but is central you the account of a One True Logic, that you have been unable to present.

Why would I take that seriously?

Beale and Restall define their pluralism in these terms for instance (and as there being "multiple true logics"), Paseau and Griffith's define their monism in these terms. — Count Timothy von Icarus

Where?

https://www.umsu.de/trees/#(~3G~5~3(P~5A)~1~3P)~5G

it's how she defines the entire problem — Count Timothy von Icarus

"Correct logic" is not a term defined in formal logic. That's rather the point here. You will not, for example, find a definition of "Correct Logic" in the Open Logic text. But you will find definitions of validity, satisfaction, truth and so on. These are the terms used by logicians when doing logic.

If you are so sure that there is a correct logic, all you need do is present it. What is the "consequence relation" that is to be found in all logics that renders them either correct or... what?

She uses "correct logic" a couple of times on the first page of Logical Nihilism and not at all in "One True Logic?". It's hardly central.

If you want to make use of the term, then you can set out what you take it to mean.

I don't see how to make sense of that quote in the light of the notion of satisfaction, which does define truth in many formal logics.

But perhaps not well.

I wasn't able to follow this.

You are welcome to go in such directions, of course. It's just not my cup of tea, too far removed from the original theme of this thread to hold much interest for me. Frankly, I think such stuff too ill-defined to be done well. That doesn't stop me occasionally indulging, of course.

The first thesis in answer to the question in the OP is, opposition to abortion derives from religious belief.

So is there anyone here who is atheist or agnostic and opposes abortion?

The second thesis is that opposition to abortion derives from essentialism, the notion that there is some statable property had by any entity that makes it what it is. On this account there is a property had by a zygote in virtue of which it has a value equal to that of an adult human. This is variously thought of as a soul, or being a person, or being a human being.

Is there anyone here who rejects essentialism and opposes abortion?

Not helpful. — praxis

Oh, I don't know. Scientism and essentialism might be seen as things that dissipate with experience.

I thought your argument was that you can tell by sight. — frank

The question was

Can anyone else say that what a person is — Fire Ologist

Note "say".

Can anyone else say that what a person is, or what a human being is, and most importantly, when either one of these pops into existence? — Fire Ologist

No.

That's the bit you are missing.

The thread has wandered around quite a bit. It might be worth returning to my opening post and the philosophical curiosities around it.

Perhaps the core issue is whether there are logical laws that hold in every case. Given boundless human creativity, it is at least conceivable that whatever one posits as a logical law, a counterexample can be constructed. Russell gives examples of counter instances for identity, And elimination, excluded middle, and modus ponens. Whether these are thought successful or not, to rule out the construction of such counter instances is claiming that there is a one true logic that permits such a ruling. Exactly how and if such a logical monism might stand is one of the themes of this thread.

The opposite view would be that there are no rules that hold in any case. On this account logical reasoning has no compulsion, being little more than a rhetorical device. Exactly how and if such logical nihilism might stand is one of the themes of this thread.

Contradicting both these is the view that while no laws that apply in every case, there may well be laws that apply in some cases. On this account there might be a logic applicable to particular case or situations, but not in all cases or situations.

Russell proceeds by considering examples of mooted laws of logic and offering counter instances. You can get an idea of these by reading the paper or watching the video mentioned on Page One. The discussion concerns formal logic, and presumes some familiarity with that terminology and method. Those seriously considering the issues of the paper, video and of this thread should have at least some background in formal logic.

The logic talks at a meta level, so it talks about sentences, represented by greek letters such as φ and ψ, phi and psi, which are part of a language Γ, together with the usual connectives logical connectives. In addition she uses the Turnstile, ⊨. This represents the logical truth of sentences, so that "⊨φ" can be read as "Phi is true", and "Γ⊨φ" can be read as "Phi is true in Gamma". The topic presumes an understanding of the idea of truth as satisfaction, and there is some mention of possible worlds. These are things that folk who presume to philosophical discussion ought at least have some clear grasp.

The argument presented is a defence of the use of logic in the face of the strength of logical nihilism. If you have an interest in the topic, please take some time to look at the video or read the article. Some who have commented here have done so without that due diligence, for reasons of their own, and so entirely miss what is going on.

Agreed.

You are learning. :wink:

Hmm. The problem is more general than that, to do with the NSW government failing to provide adequate health care in rural areas. But even given that there is no way I would trade our health system for your mess.

You slide through multiple issues without accountability.

I think the focus on the single cell is for the insult value. — frank

No, it isn't.

Hitler liked the word "vermin." — frank

Godwin's law.

I think you might not realize... — frank

You do not know what I "realise".

Why did she need an abortion? — frank

Can't women be trusted to make their own decisions when provided with professional support?

...you should... — frank

More presumption.

Why do you need to know? You don't trust her?

https://www.abc.net.au/news/2024-10-30/abortion-access-regional-australia-denying-women-health-care/104387416

I think you might not realize... — frank

Somewhat presumptuous of you.

There's more than one issue here, of course, and many an intractable problem. In todays ABC news is a report concerning problems with accessing abortion on NSW. One story is of a mother of two who traveled for two hours to a hospital for a procedure to terminate a malformed foetus at 14 weeks, but due to a misunderstanding here procedure was canceled, forcing a later term abortion. Another case was a woman who sort an abortion at nine weeks but was not supported by here doctor on conscientious grounds and eventually needed an abortion at 22 weeks.

The issue here is why folk stand against abortion at all. This is not to deny the import of when and how. But that is a seperate discussion.

Added: And both of these issues are seperate to the issue of language chosen. Your reference to Hitler was insipid.

For my part the focus on blastocysts shows the absurdity of claiming equality between two things that are so different.

And the answer is "yes" while the "offspring" is a cyst.

But you are implying a zygote has some rights, but are not clarifying what they are... — Bob Ross

Yes. The question is loaded.

Sincere, perhaps, but consistent?