more from Dale Jacquette

### Single Idea 9456

#### [catalogued under 4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic]

Full Idea

Modal logic by its very nature is not monolithic, but fragmented into multiple systems of modal qualifications, reflected in the plurality of accessibility relations on modal model structures or logically possible worlds.

Gist of Idea

Modal logic is multiple systems, shown in the variety of accessibility relations between worlds

Source

Dale Jacquette (Intro to 'Philosophy of Logic' [2002], §3)

Book Reference

'Philosophy of Logic: an anthology', ed/tr. Jacquette,Dale [Blackwell 2002], p.4

A Reaction

He implies the multiplicity is basic, and is only 'reflected' in the relations, but maybe the multiplicity is caused by incompetent logicians who can't decide whether possible worlds really are reflexive or symmetrical or transitive in their relations.