@misc{Lexicon of Arguments, title = {Quotation from: Lexicon of Arguments – Concepts - Ed. Martin Schulz, 29 Mar 2024}, author = {Stalnaker,Robert}, subject = {Barcan-Formula}, note = {I 150 Barcan formula/BF/Stalnaker: the Barcan formula involves the interaction of the universal quantifier with the necessity operator: (BF) " NF x ^ > N " x ^ F. Conversely: (CBF) N " F ^ x > " x ^ NF (Kripke 1963)(1): Kripke's semantics showed that semantic assumptions are also needed. He also showed a fallacy in the proofs that they supposedly deduced, in which these assumptions were missing. It is valid if wuU, Du < Dw, i.e. if the subject matter of the accessible possible world is a subset of the range of the output possible world - vice versa for the converse. Qualified converse of Barcan-Formula/Stalnaker: a qualified converse with the Barcon-Formula is made with the existence adoption: ( QCBF ) N "x ^ F> " x ^ N ex > F). Existence predicate e: Ey ^ (x = y ). I 151 Barcan-Formula/qualified converse/Stalnaker: if in possible world w it is necessary that everything satisfies F, then everything that must exist in w, must satisfy F in any accessible possible world, in which this individual exists. That is valid in our semantics but it is not a theorem because it is a variant of the invalid semantics. This is what we examine here. 1. S. A. Kripke, 1963. Semantical Analysis of Modal Logic I Normal Modal Propositional Calculi. Mathematical Logic Quarterly Volume 9, Issue 5‐6}, note = { Stalnaker I R. Stalnaker Ways a World may be Oxford New York 2003 }, file = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=203984} url = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=203984} }