Editing Proposition (section)

==Historical usage==

===By Aristotle===

In [[Aristotelian logic]] a proposition was defined as a particular kind of sentence (a [[declarative sentence]]) that affirms or denies a [[Predicate (grammar)|predicate]] of a [[subject (grammar)|subject]], optionally with the help of a [[Copula (linguistics)|copula]].<ref name=":1" /> Aristotelian propositions take forms like "All men are mortal" and "Socrates is a man."

[[Aristotelian logic]] identifies a [[categorical proposition]] as a sentence which affirms or denies a [[Predicate (grammar)#Traditional grammar|predicate]] of a [[Subject (grammar)|subject]], optionally with the help of a [[Copula (linguistics)|copula]].  An Aristotelian proposition may take the form of "All men are mortal" or "Socrates is a man."  In the first example, the subject is "men", predicate is "mortal" and copula is "are", while in the second example, the subject is "Socrates", the predicate is "a man" and copula is "is".<ref name=":1">{{Cite web|url=https://www.iep.utm.edu/aris-log/#H3|title=Aristotle: Logic — From Words into Propositions|last=Groarke|first=Louis|website=Internet Encyclopedia of Philosophy|access-date=2019-12-10}}</ref>

===By the logical positivists===
Often, propositions are related to [[Sentence (mathematical logic)|closed formulae (or logical sentence)]] to distinguish them from what is expressed by an [[open formula]]. In this sense, propositions are "statements" that are [[truth-bearer]]s. This conception of a proposition was supported by the philosophical school of [[logical positivism]].

Some philosophers argue that some (or all) kinds of speech or actions besides the declarative ones also have propositional content. For example, [[yes–no question]]s present propositions, being inquiries into the [[truth value]] of them. On the other hand, some [[Semiotics|sign]]s can be declarative assertions of propositions, without forming a sentence nor even being linguistic (e.g. traffic signs convey definite meaning which is either true or false).

Propositions are also spoken of as the content of [[belief]]s and similar [[propositional attitude|intentional attitudes]], such as desires, preferences, and hopes. For example,  "I desire ''that I have a new car''", or "I wonder ''whether it will snow''" (or, whether it is the case that "it will snow"). Desire, belief, doubt, and so on, are thus called propositional attitudes when they take this sort of content.<ref name=":0">{{cite web|url=http://plato.stanford.edu/entries/propositions/|title=Propositions (Stanford Encyclopedia of Philosophy)|last1=McGrath|first1=Matthew|last2=Frank|first2=Devin|website=Plato.stanford.edu|access-date=2014-06-23}}</ref>

===By Russell===
[[Bertrand Russell]] held that propositions were structured entities with objects and properties as constituents. One important difference between [[Ludwig Wittgenstein]]'s view (according to which a proposition is the set of [[possible world]]s/states of affairs in which it is true) is that on the Russellian account, two propositions that are true in all the same states of affairs can still be differentiated. For instance, the proposition "two plus two equals four" is distinct on a Russellian account from the proposition "three plus three equals six". If propositions are sets of possible worlds, however, then all mathematical truths (and all other necessary truths) are the same set (the set of all possible worlds).{{citation needed|date=November 2014}}