- possible worlds
- The central notion in the semantic or model theoretic exploration of modal logic . A possible world is here considered to be a complete state of affairs, or one in which every proposition under consideration has a definite truth-value. A proposition p is necessary (⎕p ) if it is true at all possible worlds, possible (⋄p ) if it is true at some, and impossible if it is true at none. Various relations can be defined over possible worlds. For example, to model questions arising over the iteration of modal operators, such as whether ⎕p implies ⎕hp, Kripke defined an accessibility relation over worlds, enabling him to transform this question into the issue of whether, if a proposition is true at all worlds accessible from this, then it is true at all worlds accessible from all worlds accessible from this. To give a theory of counterfactuals, David Lewis used a similarity relationship, so a counterfactual conditional ‘If p had been true, q would have been’ can be regarded as true if it is true at all of the most similar worlds to ours in which p is true.Although the utility of possible worlds models in exploring modal logic is beyond doubt, the philosophical propriety of the notion has been intensively debated, with the same kinds of position emerging as in the philosophy of mathematics : Platonism, alleging their reality (see modal realism ), forms of constructivism, alleging that we create them, and formalism, regarding the notation as a useful tool for logic but nothing more.
Philosophy dictionary. Academic. 2011.
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Possible worlds — possible worlds … Philosophy dictionary
Possible Worlds — may refer to: * Possible Worlds (play), by John Mighton ** Possible Worlds (film), by Robert Lepage, based on the Mighton play * Possible Worlds (poetry book), by Peter Porter * Possible Worlds (book), by J. B. S. Haldane … Wikipedia
Possible Worlds (play) — Possible Worlds , written in 1990 by John Mighton, is an unusual play. Part murder mystery, part science fiction, and part mathematical philosophy, it follows the multiple parallel lives of the mysterious George Barber. At the play s beginning,… … Wikipedia
Possible Worlds (film) — Possible Worlds is a 2000 Canadian film adaptation of the play of the same name. The film is directed by Robert Lepage, and stars Tom McCamus and Tilda Swinton. AwardsWon* Best Achievement in Art Direction/Production Design Genie Awards * Best… … Wikipedia
Of All Possible Worlds — First … Wikipedia
Best of all possible worlds — OptimismThe phrase the best of all possible worlds ( fr. le meilleur des mondes possibles) was coined by the German philosopher Gottfried Leibniz in his 1710 work Essais de Théodicée sur la bonté de Dieu, la liberté de l homme et l origine du mal … Wikipedia
all’s for the best in the best of all possible worlds — This saying translates Voltaire’s Tout est pour le mieux dans le meilleur des mondes possibles, the observation which the philosophical optimist Dr Pangloss in Candide (1759) persists in making, despite overwhelming evidence to the contrary. 1911 … Proverbs new dictionary
the best of all possible worlds — the best of all (possible) worlds : the best possible situation The current economic situation is the best of all possible worlds for investors. • • • Main Entry: ↑world … Useful english dictionary
(the) best of both possible worlds — the best of ˈboth/ˈall possible worlds idiom the benefits of two or more completely different situations that you can enjoy at the same time • If you enjoy the coast and the country, you ll get the best of both worlds on this walk. Main entry:… … Useful english dictionary
(the) best of all possible worlds — the best of ˈboth/ˈall possible worlds idiom the benefits of two or more completely different situations that you can enjoy at the same time • If you enjoy the coast and the country, you ll get the best of both worlds on this walk. Main entry:… … Useful english dictionary