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Full Idea
In S4 logic the actual world is, in itself, special, not just from our point of view.
Gist of Idea
In S4 the actual world has a special place
Source
Michael Dummett (Could There Be Unicorns? [1983], 8)
Book Ref
Dummett,Michael: 'The Seas of Language' [OUP 1993], p.348
A Reaction
S4 lacks symmetricality, so 'you can get there, but you can't get back', which makes the starting point special. So if you think the actual world has a special place in modal metaphysics, you must reject S5?
15544 | If what is actual might have been impossible, we need S4 modal logic [Armstrong, by Lewis] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
16958 | In S4 the actual world has a special place [Dummett] |
14671 | What is necessary is not always necessarily necessary, so S4 is fallacious [Salmon,N] |
9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
7794 | There are seven modalities in S4, each with its negation [Girle] |
15102 | S4 says there must be some necessary truths (the actual ones, of which there is at least one) [Cameron] |