|Necessity de re: is a controversial form of necessity which assumes that it can be stated about objects whether or not they necessarily have certain properties. The counter position is that necessity can only be assumed de dicto, i.e. as a property of the linguistic forms with which can be spoken about objects. See also de dicto, de re, planet example.|
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|Berka I 145
Def need / necessary / Tarski / Lukasiewicz: NMNp = NCpNp - "it is necessary that p" means "it is not true that if p, then not-p." We can claim of a statement "a" that it is necessary iff its own negation is not included in it.
Logic, Semantics, Metamathematics: Papers from 1923-38 Indianapolis 1983
K. Berka/L. Kreiser
Logik Texte Berlin 1983