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Counterfactual is counterfactual conditional, a conditional containing an if-clause which is contrary to fact.
Counterfactual may also refer to:
| Look up counterfactual in Wiktionary, the free dictionary. |
Counterfactual is counterfactual conditional, a conditional containing an if-clause which is contrary to fact.
Counterfactual may also refer to:
 | This disambiguation page lists articles associated with the title Counterfactual. If an internal link led you here, you may wish to change the link to point directly to the intended article. |
In quantum mechanics, counterfactual definiteness (CFD) is the ability to speak "meaningfully" of the definiteness of the results of measurements that have not been performed. The term "counterfactual definiteness" is used in discussions of physics calculations, especially those related to the phenomenon called quantum entanglement and those related to the Bell inequalities. In such discussions "meaningfully" means the ability to treat these unmeasured results on an equal footing with measured results in statistical calculations. It is this aspect of counterfactual definiteness that is of direct relevance to physics and mathematical models of physical systems and not philosophical concerns regarding the meaning of unmeasured results.
A thought experiment considers a hypothesis, theory, or principle for the purpose of thinking through its consequences.
A fact is an occurrence in the real world. The usual test for a statement of fact is verifiability—that is whether it can be demonstrated to correspond to experience. Standard reference works are often used to check facts. Scientific facts are verified by repeatable careful observation or measurement by experiments or other means.
The subjunctive is a grammatical mood, a feature of the utterance that indicates the speaker's attitude toward it. Subjunctive forms of verbs are typically used to express various states of unreality such as: wish, emotion, possibility, judgement, opinion, obligation, or action that has not yet occurred; the precise situations in which they are used vary from language to language. The subjunctive is one of the irrealis moods, which refer to what is not necessarily real. It is often contrasted with the indicative, a realis mood which is used principally to indicate that something is a statement of fact.
Phenomenalism is the view that physical objects cannot justifiably be said to exist in themselves, but only as perceptual phenomena or sensory stimuli situated in time and in space. In particular, some forms of phenomenalism reduce talk about physical objects in the external world to talk about bundles of sense-data.
David Kellogg Lewis was an American philosopher who is widely regarded as one of the most important philosophers of the 20th century. Lewis taught briefly at UCLA and then at Princeton University from 1970 until his death. He is closely associated with Australia, whose philosophical community he visited almost annually for more than 30 years.
Counterfactual conditionals are conditional sentences which discuss what would have been true under different circumstances, e.g. "If Peter believed in ghosts, he would be afraid to be here." Counterfactuals are contrasted with indicatives, which are generally restricted to discussing open possibilities. Counterfactuals are characterized grammatically by their use of fake tense morphology, which some languages use in combination with other kinds of morphology including aspect and mood.
Conditional sentences are sentences that express one thing contingent on something else, e.g. "If it rains, the picnic will be cancelled". They are so called because the impact of the main clause of the sentence is conditional on the dependent clause. A full conditional thus contains two clauses: the dependent clause expressing the condition, called the antecedent ; and the main clause expressing the consequence, called the consequent.
The material conditional is a logical connective that is often symbolized by a forward arrow "→". The material conditional is used to form statements of the form p → q which is read as "if p then q". Unlike the English construction "if … then …", the material conditional statement p → q does not conventionally specify a causal relationship between p and q; "p is the cause and q is the consequence from it" is not a generally valid interpretation of p → q. It merely means "if p is true then q is also true", such that the statement p → q is false only when p is true and q is false. In a bivalent truth table of p → q, if p is false then p → q is true, regardless of whether q is true or false since (1) p → q is always true as long as q is true, and (2) p → q is true when both p and q are false. This truth table is useful in proving some mathematical theorems.
The modal verbs of English are a small class of auxiliary verbs used mostly to express modality. They can be distinguished from other verbs by their defectiveness and by their neutralization.
In linguistics, irrealis moods are the main set of grammatical moods that indicate that a certain situation or action is not known to have happened at the moment the speaker is talking. This contrasts with the realis moods.
French verbs are a part of speech in French grammar. Each verb lexeme has a collection of finite and non-finite forms in its conjugation scheme.
The conditional mood is a grammatical mood used in conditional sentences to express a proposition whose validity is dependent on some condition, possibly counterfactual.
An object of the mind is an object that exists in the imagination, but which, in the real world, can only be represented or modeled. Some such objects are abstractions, literary concepts, or fictional scenarios.
The subjunctive mood in English is a clause type used in some contexts which describe non-actual possibilities, e.g. "It's crucial that you be here" and "It's crucial that he arrive early." In English, the subjunctive is syntactic rather than inflectional, since there is no specifically subjunctive verb form. Rather, subjunctive clauses recruit the bare form of the verb which is also used in a variety of other constructions.
The conditional perfect is a grammatical construction that combines the conditional mood with perfect aspect. A typical example is the English would have written. The conditional perfect is used to refer to a hypothetical, usually counterfactual, event or circumstance placed in the past, contingent on some other circumstance. Like the present conditional, the conditional perfect typically appears in the apodosis in a conditional sentence.
In linguistics, grammatical mood is a grammatical feature of verbs, used for signalling modality. That is, it is the use of verbal inflections that allow speakers to express their attitude toward what they are saying. The term is also used more broadly to describe the syntactic expression of modality – that is, the use of verb phrases that do not involve inflection of the verb itself.
Tense–aspect–mood or tense–modality–aspect is a group of grammatical categories which are important for the understanding of spoken or written content and which are marked in different ways by different languages.
This article describes the uses of various verb forms in modern standard English language. This includes:
Prototypical conditional sentences in English are those of the form "If X, then Y". The clause X is referred to as the antecedent, while the clause Y is called the consequent. A conditional is understood as expressing its consequent under the temporary hypothetical assumption of its antecedent.