User:Peter Damian/Sense and reference

See Sense and reference The distinction between sense and reference was an innovation of the German philosopher and mathematician Gottlob Frege in 1892, reflecting the two ways he believed a singular term may have meaning. The reference (or "referent", German: bedeutung)) of a proper name is the object it means or indicates (bedeuten), its sense is what the name expresses. The reference of a sentence is its truth value, its sense is the thought that it expresses. Frege justified the distinction in a number of ways.
 * 1) Sense is something possessed by an name, whether or not it has a reference. For example the name "Odysseus" is intelligible, and therefore has a sense, even though there is no individual object (its reference) to which the name corresponds.
 * 2) Sense is wholly semantic. Reference by contrast, though also semantic, is intimately connected with the named object. Frege argues that Mont Blanc "with its snowfields" cannot be a component of the thought that Mont Blanc is more than 4,000 metres high. But if we find the same word in two sentences, e.g. "Etna", then we also we recognise something common to the corresponding thoughts, something corresponding to the word "Etna".
 * 3) The sense of different names is different, even when their reference is the same. Frege that if an identity statement such as "Hesperus is the same planet as Phosphorus" is to be informative, the proper names flanking the identity sign must have a different meaning or sense. But clearly, if the statement is true, they must have the same reference. The sense is a 'mode of presentation', which serves to illuminate only a single aspect of the referent.

Background
Frege developed his original theory of meaning in early works like the Begriffsschrift ('concept script') of 1879 and the Grundlagen ('foundations of arithmetic') of 1884. On this theory, the meaning of a complete sentence consists in its being true or false, and the meaning of each significant expression in the sentence is an extralinguistic entity which Frege called its Bedeutung, literally 'meaning' or 'significance', but rendered by Frege's translators as 'reference', 'referent', 'Meaning', 'nominatum' etc. Frege supposed that some parts of speech are complete by themselves, and are analogous to the arguments of a mathematical function, but that other parts are incomplete, and contain an empty place, by analogy with the function itself. Thus 'Caesar conquered Gaul' divides into the complete term 'Caesar', whose reference is Caesar himself, and the incomplete term '—conquered Gaul', whose reference is a Concept. Only when the empty place is filled by a proper name does the reference of the completed sentence – its truth value – appear. This early theory of meaning explains how the significance or reference of a sentence (its truth value) depends on the significance or reference of its parts.

Sense
Frege introduced the notion of Sense (German: Sinn) to accommodate difficulties in his early theory of meaning. First, if the entire significance of a sentence consists in its truth value, it follows that the sentence will have the same significance if we replace a word of the sentence with one having an identical reference, for this will not change the truth value of the sentence. The reference of the whole is determined by the reference of the parts. If 'the evening star' has the same reference as 'the morning star', it follows that 'the evening star is a body illuminated by the Sun' has the same truth value as 'the morning star is a body illuminated by the Sun'. But someone may think that the first sentence is true, but the second is false, and so the thought corresponding to the sentence cannot be its reference, but something else, which Frege called its sense. Second, sentences which contain proper names that have no reference cannot have a truth value at all. Yet the sentence 'Odysseus was set ashore at Ithaca while sound asleep' obviously has a sense, even though 'Odysseus' has no reference. The thought remains the same whether or not 'Odysseus' has a reference.

Frege's notion of sense is somewhat obscure, and neo-Fregeans have come up with different candidates for its role. Accounts based on the work of Carnap and Church treat sense as an intension, or a function from possible worlds to extensions. For example, the intension of ‘number of planets’ is a function that maps any possible world to the numbers to the the number of planets in that world. McDowell supplies cognitive and reference-determining roles. Devitt treats senses as causal-historical chains connecting names to referents.

There are well-known objections to sense theories of proper names. According to Kripke, names are rigid designators whose intension is constant across possible worlds. For example, it is true to say that Aristotle might not have been the teacher of Alexander, but false to say that Aristotle might not have been Aristotle. But the intension of ' the teacher of Alexander' will be different across different possible worlds.

Translation of Bedeutung
As noted above, translators of Frege have rendered the German Bedeutung in various ways. The term 'reference' has been the most widely adopted, but this fails to capture the meaning of the original German ('meaning' or 'significance'), and does not reflect the decision to standardise of key terms across different editions of Frege's works published by Blackwell. The decision was based on the principle of exegetical neutrality, namely that 'if at any point in a text there is a passage that raises for the native speaker legitimate questions of exegesis, then, if at all possible, a translator should strive to confront the reader of his version with the same questions of exegesis and not produce a version which in his mind resolves those questions'. The term 'meaning' best captures the standard German meaning of Bedeutung, and Frege's own use of the term sounds as odd when translated into English as it does in German. Also, 'meaning' captures Frege's early use of Bedeutung well. , and it would be problematic to translate Frege's early use by 'meaning', and his later use by 'reference', suggesting a change in terminology not evident in the original German.

Relation to connotation and denotation
The sense-reference distinction is commonly confused with that between connotation and denotation, which originates with Mill. According to Mill, a common term like 'white' denotes all white things, as snow, paper'. But according to Frege, a common term does not refer to any individual white thing, but rather to an abstract Concept (Begriff). We must distinguish between the relation of reference, which holds between a proper name and the object it refers to, such as between the name 'Earth', and the planet Earth, and the relation of 'falling under', such as when the Earth falls under the concept planet. The relation of a proper name to the object it designates is direct, whereas a word like 'planet' has no such direct relation at all to the Earth at all, but only to a concept that the Earth falls under. Moreover, the judgment that anything falls under this concept is not in any way part of our knowledge of what the word 'planet' means. The distinction between connotation and denotation is closer to that between Concept and Object, than to that between 'sense' and 'reference'.