Proposition
Proposition
This word has been used to mean
a declarative sentence (in some particular language);
the content of meaning of a declarative sentence, i e., a postulated abstract object common not only to different occurrences of the same declarative sentence but also to different sentences (whether of the same language or not) which are synonymous or, as we say, mean the same thing;
a declarative sentence associated with its content of meaning.
Often the word proposition is used ambiguously between two of these meanings, or among all three.
The Port-Royal Logic defines a proposition to be the same as a judgment but elsewhere speaks of propositions as denoting judgments. Traditional logicians generally have defined a proposition as a judgment expressed in words, or as a sentence expressing a judgment, but some say or seem to hold in actual usage that synonymous or intertranslatable sentences represent the same proposition. Recent writers in many cases adopt or tend towards (b).
In articles in this dictionary by the present writer the word proposition is to be understood in sense (b) above. This still leaves an element of ambiguity, since common usage does not always determine of two sentences whether they are strictly synonymous or merely logically equivalent. For a particular language or logistic system, this ambiguity may be resolved in various ways. — A.C.