• A -> not-A
    I suspect you don't know what is meant by 'interpretation'.TonesInDeepFreeze

    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? It doesn't say anything in that case.
  • A -> not-A
    I didn't change any premises. And I didn't make anything true or false. I merely pointed out that A -> ~A is true in the interpretation in which A is false.TonesInDeepFreeze

    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 doesn't say anything at all if A is false. It's trivially true.

    So the conclusion to the argument should be the 2nd premise. It should be A.
  • A -> not-A


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


    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 A is false, they both have to be false.
  • A -> not-A
    The conclusion always comes out as not-A. Tones is basically swapping the first premise out with a different one by considering an "interpretation" where A is false.

    In other words, you can interpret that cows can bark if you want to.
  • A -> not-A


    Yea, you're right.
  • A -> not-A



    "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, so the conditional in premise 1 is false.

    How would you be warranted to examine what happens when A is false?
  • A -> not-A

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


    Isn't the first premise: If A, then not-A? That's what it looks like
  • A -> not-A
    (1) The first premise in that argument is not necessarily false.TonesInDeepFreeze

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

    I think the first premise is necessarily false in propositional logic.
  • A -> not-A


    So we know the first premise is necessarily false. That means the conclusion has to be false for validity. Is the conclusion false?
  • A -> not-A
    If a premise is necessarily false, then the argument is valid.TonesInDeepFreeze

    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 argument in terms of validity?
  • A -> not-A


    But what if you say the first premise is necessarily false? It can't be true. Then what do you get?
  • A -> not-A
    (1) both A and ~A can be derived from the premises,Hanover

    How are you getting A as a conclusion?
  • A -> not-A


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

    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 of some religions. Religions serve other purposes as well.
  • Donald Trump (All General Trump Conversations Here)


    Yay! Let's go take over a government building!
  • Logical Nihilism

    What are your thoughts on logical pluralism?
  • Logical Nihilism

    You're just not going to read anything about it. That's cool. :up:
  • Logical Nihilism
    do not think it's plausible to say that trivial logics in which everything expressible can be proven true are only arbitrarily bad for inference for instance. Do you disagree?Count Timothy von Icarus

    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 further examination. I found myself getting more of a handle on it when reading the objections to it. It's all pretty technical, and that's not really something I'm super familiar with, but I did get that logical pluralism isn't taking anything away from the regular logic.

    I get that you're preoccupied with issues surrounding truth, but that's not a significant aspect of this issue. Check out the SEP article if you want.
  • Abortion - Why are people pro life?
    I said when viewed in it's own era a majority opinion is reasonable.LuckyR

    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?
  • Logical Nihilism
    And can one have correct purposes, or can one's purposes be defined arbitrarily? The purpose here is to capture natural language understandings of good reasoning and valid argumentCount Timothy von Icarus

    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 natural language. Are you saying I can't have that because of your sensibilities?
  • Logical Nihilism
    What is "appropriateness" then?Count Timothy von Icarus

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


    "Correct" in that quote basically means appropriate. It has nothing to do with truth.
  • Abortion - Why are people pro life?
    Thus why a moral stance that enjoys majority acceptance, when evaluated in it's own era, the majority acceptance signifies that the moral stance is reasonableLuckyR

    Majority acceptance does not signify that a moral stance is right. That's what matters.
  • Abortion - Why are people pro life?

    Your posts show why it's such an emotionally charged topic. :strong:
  • Monistic systems lead to explosion
    Might it be that you are thinking of the question in too narrow a way and not they collectively misunderstanding it?Count Timothy von Icarus

    Since I don't know who they were or why they responded as they did, there's no way to resolve the question.

    Which topic? It remains the most popular conception in metaphysics, of that I'm quite confident.Count Timothy von Icarus

    What makes you think this?

    What's the demonstration?Count Timothy von Icarus

    I'm in the middle of a project. I think you'd find Soames' book to be a great investment. Plus you can get his books about the history of AP, although he said something about Davidson that didn't turn out to be correct.
  • Monistic systems lead to explosion
    Ok, but to be clear, it's not anonymous, it's just confidential. That is how they're able to do longitudinal analysis.Count Timothy von Icarus

    Either the folks who responded that they accept correspondence theory didn't understand the question, or they interpreted "correspondence" in some creative way. Correspondence is not accepted by anyone who's familiar with the topic. It's fairly straightforward to demonstrate that truth can't be analyzed in that way. Believe it or don't. :wink:
  • Monistic systems lead to explosion
    Well, the 2009 survey results are pretty similar and those were based on the academic departments/sub-departments people work in at the top programs from Philosophical Gourmet Report. If there was a sampling error in the broader 2020 population, it just seems like it would vary more from the broader pollingCount Timothy von Icarus

    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 what they're saying. I don't think you want to take anonymous data over an actual overview of the topic by a recognized specialist like Soames.
  • Monistic systems lead to explosion

    If you're interested in the topic, I recommend an overview of philosophy of truth since Frege. A good one is Understanding Truth by Scott Soames. I get that I'm just some random stranger on the internet, but for what it's worth, I'm telling you there's a big misunderstanding looming in your view on this.
  • Monistic systems lead to explosion
    I suppose one interesting thing is that correspondence still enjoys a majority for specialists in logicCount Timothy von Icarus

    This is definitely not true. I'd suggest we get to the bottom of what your data is actually showing. Who are the respondents?
  • Monistic systems lead to explosion

    Can you get one of those paper referred to there so we can see what they're talking about?
  • Monistic systems lead to explosion

    Neoliberalism didn't come from post-modernism. It came from Hayek and brainless western leftists.

    Anyhow, there are many options aside from correspondence.Count Timothy von Icarus

    True enough.
  • Monistic systems lead to explosion
    Well, historically, this is how logic was developed (both Aristotlean and the parallel Stoic development).Count Timothy von Icarus

    Our world is profoundly Cartesian, though.

    Questions of truth sit in the bucket of "metaphysics," and generally lie external to logic. Obviously, they are related, since we have the questions: "what does it mean to reason from true premises to necessarily true conclusions," or "what are we preserving in truth-preserving arguments?" But, in general, the claim isn't that a logic is defining truth, except instrumentally.Count Timothy von Icarus

    I wasn't talking about monism leading to delusion about the world, but about the nature of thought. I guess it's more a philosophical issue rather than the danger people will walk into telephone poles. :cool:

    This is why there were charges from Putnam and others that STT was "philosophically sterile."Count Timothy von Icarus

    Deflationists would take that as a compliment. There hasn't been any serious attempt to go back to correspondence theory. It's defunct.
  • Monistic systems lead to explosion

    Just to exercise my understanding of Cheshire's view, he's using "foundationalism" to refer to an approach that builds up from within. It's a Cartesian view that our foundations are deep within our minds, waiting to be revealed through contemplation. Descartes, through the wax exercise, shows that true understanding does not come from the senses, but from the mind.

    Cheshire is saying that this view, that may cement logical monism, especially in the sense of using logical principles as laws, is an internalist conceit. Cheshire points to the way classical logic is self-contained and self-protecting. It's a castle built on air, and potentially leaving us deluded.

    Cheshire would prefer to see us start from where we are, here in the world, with our problems in view instead of down in a brain-vat.
  • Climate Change (General Discussion)
    Skepticism without grounding in unbiased reasoning and having an insight into what the science means... is meaningless.Christoffer

    Right. Educate yourself. That's the best way to gain immunity from click bait.
  • Abortion - Why are people pro life?
    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?
    Banno

    It's probably mostly religious groups that spearhead pro-life. OP answered. Shrug?
  • Logical Nihilism
    if we accept contradiction into our reasoning,Moliere

    What would be an example of that?