@misc{Lexicon of Arguments, title = {Quotation from: Lexicon of Arguments – Concepts - Ed. Martin Schulz, 29 Mar 2024}, author = {Cresswell,Maxwell J.}, subject = {Barcan-Formula}, note = {Hughes I 128 Barcan-Formula/BF/Kripke: takes for each possible world an individual domain, giving it a semantics, where in contrast to our the Barcan formula is not valid. >Accessibility), >Possible worlds. Accessibility/LewisVsKripke: with Lewis accessibility runs via individuals, therefore the Barcan formula for Lewis is valid. >Counterpart theory, >Counterpart relation, >Possible worlds/Lewis. Hughes I 150f Barcan-Formula/possible worlds/Semantik/Hughes/Cresswell : Barcan formula is invalid in semantics that assign d different domains of individuals to different possible worlds. Cf. >Possible world semantics. Hughes I 150f Barcan-Formula/Hughes/Cresswell: Vs: that everything that exists is necessary f, does not exclude that there could be things (or could have been ), not-f . Then it would not be a necessary truth that everything is f. VsVs: this proceeds from the assumption that objects not only may have other properties in different possible worlds, but that there might even be objects that do not exist in the actual world. >Extension of the > existence predicate, >Existence, >"There is". Hughes I 156 Barcan-Formula/existence/possible worlds/Hughes/Cresswell: three perspectives: a) all possible worlds have the same domain of individuals: The Barcan formula is then valid (which include T and S4) objects are the same, properties and relations change b) new things arise: Barcan formula is invalid in any case concerning T and S4 c) even more liberal: objects can be removed. >Systems S4/S5, >Individual domain.}, note = { Cr I M. J. Cresswell Semantical Essays (Possible worlds and their rivals) Dordrecht Boston 1988 Cr II M. J. Cresswell Structured Meanings Cambridge Mass. 1984 Hughes I G.E. Hughes Maxwell J. Cresswell Einführung in die Modallogik Berlin New York 1978 }, file = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=203924} url = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=203924} }