Skip to content
Carmelics
TopicsThinkersChangesContributorsLoading account…

    Carmelics

    A reasoning platform. Break down any belief into clear reasons, explore both sides, and weigh the evidence honestly.

    Navigate

    • Topics
    • Search
    • Recent Changes
    • Contribute
    • How It Works
    • Glossary
    • Thinkers
    • Contributors
    • About
    • Statistics
    • Terms
    • Privacy

    Database

    Statements
    —
    Perspectives
    —
    Topics
    —

    Press ? for keyboard shortcuts

    LoyalLoyalJusticeJustice
    Made withinDC&Austin
    Statements
    321,452
    Perspectives
    108,905
    Topics
    42
    Home/Original/inverse
    See Original
    Inverse View

    It is not the case that CBF (Converse Barcan Formula) is unprovable in KQML

    ?Set your confidence on the premises below to see your aggregate.

    Reasons For

    2 perspectives
    Reason for 1 of 2
    ?
    • 1.KQML's soundness proof applies only to closed formulas, leaving open whether CBF is provable for open formulas under extended interpretations.
      ?

      Think about whether this reason is strong or weak

    • 2.Garson and others have shown that quantified modal logics admit multiple non-equivalent semantics, so 'KQML's semantics' is not a uniquely fixed target.
      ?

      Think about whether this reason is strong or weak

    • 3.If CBF is evaluated under a constant-domain semantics rather than varying-domain Kripke semantics, it becomes valid, making unprovability relative to semantic choice, not absolute.
      ?

      Think about whether this reason is strong or weak

    Reason for 2 of 2
    ?
    • 1.Timothy Williamson's necessitism entails that every individual necessarily exists, which validates CBF across all possible worlds without exception.
      ?

      Think about whether this reason is strong or weak

    • 2.If necessitism is coherent and CBF follows from it, then a system augmented with necessitist axioms would render CBF provable, undermining the claim's generality.
      ?

      Think about whether this reason is strong or weak

    Reasons Against

    1 perspective
    Reason against
    ?
    • 1.KQML is sound relative to Kripke's semantics for closed formulas
      ?

      Think about whether this reason is strong or weak

    • 2.Soundness guarantees that no invalid formula is provable in a sound deductive system
      ?

      Think about whether this reason is strong or weak

    • 3.CBF is invalid in KQML's semantics
      ?

      Think about whether this reason is strong or weak

    Next step

    Based on where you are in your exploration

    Strongest counterpoint
    Explore the most compelling reason on the other side.