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Impossibility (other)
Impossibility may refer to: Philosophy and logic *Epistemic impossibility, in modal logic a statement that cannot be true, given what we know *Subjunctive impossibility, types of statement that cannot be true based on various types of subjunctive modality **Logical impossibility, a statement that contains a logical contradiction *Impossible world, a concept in philosophical logic Other uses *Impossibility of performance, in contract law an excuse for non-performance of a contract *Impossibility defense, a criminal defense for a crime that was legally impossible to commit *Proof of impossibility, in mathematics a proof that demonstrates that a particular problem cannot be solved See also * Impossible (other) Impossible, Imposible or Impossibles may refer to: Music * ''ImPossible'' (album), a 2016 album by Divinity Roxx * ''The Impossible'' (album), a 1981 album by Ken Lockie Groups * The Impossibles (American band), a 1990s indie-ska group from A ... * Possibility ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epistemic Impossibility
In philosophy and modal logic, epistemic possibility relates a statement under consideration to the current state of our knowledge about the actual world: a statement is said to be: * ''epistemically possible'' if it ''may be true, for all we know'' * ''epistemically necessary'' if it is ''certain'' (or ''must be the case), given what we know'' * ''epistemically impossible'' if it ''cannot be true, given what we know'' Epistemic possibility is often contrasted with subjunctive possibility (or alethic possibility), and although epistemic and subjunctive possibilities are often expressed using the same modal terms (such as ''possibly'', ''could be'', ''must be'') or similar modal terms that are sometimes confused (such as ''may be'' and ''might be''), statements that are qualified in terms of epistemic possibility and statements that are qualified in terms of subjunctive possibility have importantly different meanings. The contrast is best explained by example. Consider the two st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subjunctive Impossibility
Subjunctive possibility (also called alethic possibility) is a form of modality studied in modal logic. Subjunctive possibilities are the sorts of possibilities considered when conceiving counterfactual situations; subjunctive modalities are modalities that bear on whether a statement ''might have been'' or ''could be'' true—such as ''might'', ''could'', ''must'', ''possibly'', ''necessarily'', ''contingently'', ''essentially'', ''accidentally'', and so on. Subjunctive possibilities include logical possibility, metaphysical possibility, nomological possibility, and temporal possibility. Subjunctive possibility and other modalities Subjunctive possibility is contrasted with (among other things) epistemic possibility (which deals with how the world ''may'' be, ''for all we know'') and deontic possibility (which deals with how the world ''ought'' to be). Epistemic possibility The contrast with epistemic possibility is especially important to draw, since in ordinary language t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logical Impossibility
Logical possibility refers to a logical proposition that cannot be disproved, using the axioms and rules of a given system of logic. The logical possibility of a proposition will depend upon the system of logic being considered, rather than on the violation of any single rule. Some systems of logic restrict inferences from inconsistent propositions or even allow for true contradictions. Other logical systems have more than two truth-values instead of a binary of such values. Some assume the system in question is classical propositional logic. Similarly, the criterion for logical possibility is often based on whether or not a proposition is contradictory and as such, is often thought of as the broadest type of possibility. In modal logic, a logical proposition is possible if it is true in some possible world. The universe of "possible worlds" depends upon the axioms and rules of the logical system in which one is working, but given some logical system, any logically consistent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impossible World
In philosophical logic, the concept of an impossible world (sometimes called a non-normal world) is used to model certain phenomena that cannot be adequately handled using ordinary possible worlds. An impossible world, i, is the same sort of thing as a possible world w (whatever that may be), except that it is in some sense "impossible." Depending on the context, this may mean that some contradictions, statements of the form p \land \lnot p are true at i, or that the normal laws of logic, metaphysics, and mathematics, fail to hold at i, or both. Impossible worlds are controversial objects in philosophy, logic, and semantics. They have been around since the advent of possible world semantics for modal logic, as well as world based semantics for non-classical logics, but have yet to find the ubiquitous acceptance, that their possible counterparts have found in all walks of philosophy. Argument from ways Possible worlds Possible worlds are often regarded with suspicion, which is why ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impossibility Of Performance
The doctrine of impossibility or impossibility of performance or impossibility of performance of contract is a doctrine in contract law. In contract law, impossibility is an excuse for the nonperformance of duties under a contract, based on a change in circumstances (or the discovery of preexisting circumstances), the nonoccurrence of which was an underlying assumption of the contract, that makes performance of the contract literally impossible. For example, if Ebenezer contracts to pay Erasmus £100 to paint his house on October 1, but the house burns to the ground before the end of September, Ebenezer is excused from his duty to pay Erasmus the £100, and Erasmus is excused from his duty to paint Ebenezer's house; however, Erasmus may still be able to sue under the theory of unjust enrichment for the value of any benefit he conferred on Ebenezer before his house burned down. The parties to a contract may choose to ignore impossibility by inserting a hell or high water cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impossibility Defense
An impossibility defense is a criminal defense occasionally used when a defendant is accused of a criminal attempt that failed only because the crime was factually or legally impossible to commit. Factual impossibility is rarely an adequate defense at common law. This is not to be confused with a "mistake of fact" defense, which may be a defense to a specific intent crime like larceny. Factual impossibility An impossibility occurs when, at the time of the attempt, the facts make the intended crime impossible to commit although the defendant is unaware of this when the attempt is made. In '' People v. Lee Kong'', the defendant was found guilty for attempted murder for shooting at a hole in the roof, believing his victim to be there, and indeed, where his victim had been only moments before but was not at the time of the shooting. Another case involving the defense of factual impossibility is '' Commonwealth v. Johnson'', in which a psychic healer was charged and convicted o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Impossibility
In mathematics, an impossibility theorem is a theorem that demonstrates a problem or general set of problems cannot be solved. These are also known as proofs of impossibility, negative proofs, or negative results. Impossibility theorems often resolve decades or centuries of work spent looking for a solution by proving there ''is'' no solution. Proving that something is impossible is usually much harder than the opposite task, as it is often necessary to develop a proof that works in general, rather than to just show a particular example. Impossibility theorems are usually expressible as negative existential propositions or universal propositions in logic. The irrationality of the square root of 2 is one of the oldest proofs of impossibility. It shows that it is impossible to express the square root of 2 as a ratio of two integers. Another consequential proof of impossibility was Ferdinand von Lindemann's proof in 1882, which showed that the problem of squaring the circle cannot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impossible (other)
Impossible, Imposible or Impossibles may refer to: Music * ''ImPossible'' (album), a 2016 album by Divinity Roxx * ''The Impossible'' (album), a 1981 album by Ken Lockie Groups * The Impossibles (American band), a 1990s indie-ska group from Austin, Texas * The Impossibles (Australian band), an Australian band * The Impossibles (Thai band), a 1970s Thai rock band Songs * "Impossible" (Captain Hollywood Project song) (1993) * "The Impossible" (song), a country music song by Joe Nichols (2002) * "Impossible" (Edyta Górniak song) (2003) * "Impossible" (Kanye West song) (2006) * "Impossible" (Travis Scott song) (2015) * "Impossible" (Daniel Merriweather song) (2009) * "Impossible" (Måns Zelmerlöw song) (2009) * "Impossible" (Anberlin song) (2010) * "Impossible" (Shontelle song) (2010), covered by James Arthur (2012) * "Impossible", from Rodgers and Hammerstein's 1957 musical '' Cinderella'' * "Impossible", a song written by Steve Allen and recorded by Nat King Cole fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |