extension

extension, in logic, correlative words that indicate the reference of a term or concept: “intension” indicates the internal content of a term or concept that constitutes its formal definition; and “extension” indicates its range of applicability by naming the particular objects that it denotes. For…

As noted above, reference is an apparent relation between a word and the world. Russell, following the 19th-century British philosopher John Stuart Mill, pursued the intuition that linguistic expressions are signs of something other than themselves. He suggested that the meaning of an…

…determined according to the standard interpretation of logical connectives. For example, p · q is true if and only if p and q are true. (Here, the dot means the conjunction “and,” not the multiplication operation “times.”) Thus, given any interpretation of a formal language, a formal concept of truth…

…notation to explore quantities (“extensions”) of all sorts—logical extension and intension, numerical, spatial, temporal, and so on. Grassmann’s notion of extension is very similar to the use of the broad term “quantity” (and the phrase “logic of quantity”) that is seen in the works of George Bentham and Sir…

…the distinction between comprehension and extension. Although medieval semantic theory had used similar notions, the Port-Royal notions found their way into numerous 18th- and 19th-century discussions of the meanings and reference of terms; they appeared, for example, in John Stuart Mill’s influential text A System of Logic (1843). The “comprehension”…

…account for the phenomenon of reference. Reference is a characteristic of many expressions whereby they seem to “reach out” into the world to pick out, name, designate, apply to, or denote different things. Although the appearance of connection between words and the world is familiar to anyone who speaks a…

…terms turns on whether their extensional or intensional attributes are in play; extension designates the set of individuals to which a term applies, while intension describes the set of attributes which define the term. The term that fills the first blank is called the subject of the proposition, that which…