Semantics for Quantified Modal Logic

Quantified modal logic is the combination of first-order logic and modal logic. In this video, we look at how to combine first-order and modal semantics to build models for QML.
00:00 - Intro
00:59 - Models for FOL and modal logic
01:46 - Models for QML
03:25 - How to use QML models
04:37 - Second example
05:39 - Third example
06:32 - Different modal systems
07:37 - QML semantics in full
08:29 - Truth in a model
09:29 - Constant Domain Semantics
11:38 - Problems for Constant Domain Semantics
12:49 - Wrap-Up
More videos on modal logic coming next! If there’s a topic you’d like to see covered, leave me a comment below.
Links:
My academic philosophy page: markjago.net
My book What Truth Is: bit.ly/JagoTruth
Most of my publications are available freely here: philpapers.org/s/Mark%20Jago
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Instagram: / atticphilosophy
Twitter: / philosophyattic
#logic #philosophy #possibility

[@kaipaul7667]

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[@AtticPhilosophy]

Thanks! Yes, more hype please!

[@ericd9827]

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[@AtticPhilosophy]

Glad you like them!

[@ZishanWazedBegg]

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[@AtticPhilosophy]

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[@AtticPhilosophy]

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[@hansonmanfred2928]

Concerning the issue brought up at 11:37, does anyone know why one could not just have a constant domain model possessing all of the possible objects contained in all possible worlds, then equip each possible world with an existence property?

[@AtticPhilosophy]

That’s definitely an option. There are philosophical questions: is there a property of existence? What does the quantified mean, if not ‘exists’? And there’s logical questions: if the universal quantifier quantifies over all possible entities, then true universals will be hard to get. In effect, there won’t be contingent universal truths.

[@quantum-atom]

7:30 It's serial. It's D.

[@AtticPhilosophy]

Sounds good to me!