Carnap Rudolf. Meaning and Necessity: A Study in Semantics and Modal Logic

The University of Chicago Press, 1948. — viii, 210 pages.The main purpose of this book is the development of a new method for the semantical analysis of meaning, that is, a new method for analyzing and describing the meanings of linguistic expressions. This method, called the method of extension and intension, is developed by modifying and extending certain customary concepts, especially those of class and property. The method will be contrasted with various other semantical methods used in traditional philosophy or by contemporary authors. These other methods have one characteristic in common. They all regard an expression in a language as a name of a concrete or abstract entity. In contradistinction, the method here proposed takes an expression, not as naming anything, but as possessing an intension and an extension.The Method of Extension and Intension
Preliminary Explanations
L-Concepts
Equivalence and L-Equivaience
Classes and Properties
Extensions and Intensions
Extensions and Intensions of Sentences
Individual Descriptions
Frege's Method for Descriptions
Extensions and Intensions of Individual Expressions
Variables
Extensional and Intensional Contexts
The Principles of Interchangeability
Sentences about Beliefs
Intensional Structure
Applications of the Concept of Intensional Structure
Lewis' Method of Meaning Analysis
L-Determinacy
L-Determinate Designators
The Problem of L-Determinacy of Individual Expressions
Definition of L-Determinacy of Individual Expressions
L-Determinacy of Predicators
Logical and Descriptive Signs
L-Determinate Intensions
Reduction of Extensions to Intensions
The Method of the Name-Relation
The Name-Relation
An Ambiguity in the Method of the Name-Relation
The Unnecessary Duplication of Names 106
Names of Classes
Frege's Distinction between Nominal turn and Sense
Nomination and Sense: Extension and Intension
The Disadvantages of Frege's Method
The Antinomy of the Name-Relation
Solutions of the Antinomy
On Metalanguages for Semantics
The Problem of a Reduction of the Entities
The Neutral Metalanguage M'
M' Is Not Poorer than M
Neutral Variables in M'
On the Formulation of Semantics in the Neutral Metalanguage M'
On the Possibility of an Extensional Metalanguage for Semantics
On the Logic of Modalities
Logical Modalities
Modalities and Variables
Semantical Rules for the Modal System S2
Modalities in the Word Language
Modalities and Variables in the Word Language
Quine on Modalities
Conclusions