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Glite Dictionary
modal logic

modal logic

9.2
A type of reasoning that studies what must be true or may be true
  • noun
  • /ˈmoʊdəl ˈlɒdʒɪk/
  • Specialized
translation icon : lógica modal
  • Fictional worlds, like possible worlds in modal logic, are established through semiotic channels.

Now there's, there's another wrinkle too, which is we can talk about modal logic as well.

Examples

  • If you think S5 is the correct modal logic, and if you think that you can use individual constants like JW=YOU J. W. Wartick, then it is quite easy (the proof is in the post I linked to above).

    Blog text (24)

  • As an undergraduate, he studied modal logic.

    Blog text (14)

  • Well, no, I mean modal logic is useful enough and possible, right?

  • I'm going to run a modal logic group during the summer.

    Blog text (27)

  • Yeah, We have to keep in mind that in those years, Quine had argued against the intelligibility of modal logic because it is not extensional.

  • By contrast, in order to investigate the possible worlds of modal logic, we have to employ essentially logical devices, consistent and systemic.

    Academic text (2006)

  • Lewis spent two years immersed in the manuscripts and wrote an editorial plan before giving the project up to pursue his own work in modal logic.

    Academic text (1994)

  • Part of the problem here, as with other discussions of Leibniz's theodicy, is the conflict between Leibniz's way of conceiving possible worlds and that familiar from recent treatments of semantics for modal logic.

    Academic text (1998)

  • Many philosophers explore the principles of modal logic to analyze possible worlds.

  • Courses on modal logic often examine concepts of necessity and possibility in depth.

Surface Forms

modal logic singular
modal logics plural

Morphology

modal + logic

The compound is compositionally built: 'modal' (relating to modality/expressing necessity or possibility) combined with 'logic' (the study of reasoning) yields a logic about modality. Although a technical term, its meaning follows directly from the constituents and similar formations occur cross-linguistically, so a B1 learner who knows both words can infer the intended sense.

Etymology

Modal logic comes from modal (ways of saying 'must' or 'might') and logic (reasoning). Imagine two doors: locked doors show what is 'necessary' and open doors show what is 'possible', so modal logic studies what must be true and what might be true.