lecture 3 by goodbaby

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									Stefano Predelli - Spring 2009

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LECTURE 3

Compositionality
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Frege’s compositionality principles Compositionality of reference. E.g. the referent for ‘the wife of David’ depends on the referent of ‘David’. Similarly, the referent for (1) ‘the wife of D is wise’ depends on the referent for ‘the wife of D’. The feature of (1) that is affected by the referent of ‘the wife of D’: its truth-value

Stefano Predelli - Spring 2009

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Frege: the truth-value of a sentence as its referent Sentences only have two referents, the True and the False (Church-Gödel: the slingshot) As we shall see, not all expressions have a referent. Similarly, for Frege, some sentences are neither true nor false. (More later)

Stefano Predelli - Spring 2009

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Compositionality of sense: the sense of a complex expression depends on the sense of its components Exchanging one expression for another with same referent but different sense, as in ‘the PM is wise’ ‘the husband of S is wise’ leaves truth-value unaffected, but changes the ‘information content’, the expressed thought Frege: the sense of a sentence is a thought

Stefano Predelli - Spring 2009

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We can grasp ‘novel expressions’ (Chomsky, Wittgenstein, ...) ‘there are no pink elephants in my pocket’ Frege: compositionality of sense. Having grasped the sense of the simple expressions (knowledge of the language?), we can thereby grasp the thought

Stefano Predelli - Spring 2009

Non-Referring Expressions
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expression (sign) – sense – reference for each non-ambiguous (meaningful) expression there corresponds a sense, and for each sense, there may correspond a referent ‘the least rapidly convergent series’, ‘the king of England in 2009’, ‘the largest prime number’, ‘Santa Claus’ ‘in grasping a sense, one is not certainly assured of a reference’

Stefano Predelli - Spring 2009

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An advantage for Frege’s theory? Sentences containing non-referring terms are intelligible. Contrast ‘the English king is wise’ ‘xfdgs is wise’ The first ‘says something’, expresses a thought, even though it contains a non-ref term (and hence is neither true nor false) This would not be explainable on the simple view, according to which all there is to sing terms is reference

Stefano Predelli - Spring 2009

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Similarly ‘Santa Claus is jolly’ expresses a thought, but is neither true nor false (you won’t find Santa either among the jolly individuals or among the nonjolly ones) Frege: rejection of bivalent semantics (Strawson: presupposition semantics)

Stefano Predelli - Spring 2009

Indirect Reference
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‘If words are used in the ordinary way, what one intends to speak of is their reference. It can also happen, however, that one wishes to talk about the words themselves or their sense’ Talking about the words: quotation. (Frege’s theory of quotation: ‘words ... designate words ...’ The identity-theory of quotation?) Talking about sense: ‘reported speech’

Stefano Predelli - Spring 2009

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The problem of reported speech (attitude reports). Suppose that David thinks that Sarah is married to John, and hence rejects ‘the PM is the husband of S’. Then ‘David believes that the PM is the husband of S’ ‘David believes that the PM is the PM’ have contrasting truth-values. But they differ only for co-ref expressions. A counter-example to compositionality of reference?

Stefano Predelli - Spring 2009

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Remember: truth-value depends on reference So, substitutions of co-ref terms cannot affect truth-value Substitutivity: if a and b corefer, they can be substituted salva veritate (Sa is true iff Sb is) The apparent counter-example of attitude reports

Stefano Predelli - Spring 2009

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Frege: a theory of reference-shift ‘It is quite clear that in [reported speech] words do not have their customary reference but designate what is usually their sense’ The referent of an expression depends on where it occurs. Better: talk of the referent of an occurrence of an expression What is the referent of ‘the PM’? When it occurs in ‘the PM is wise’, it is Gordon. When it occurs in ‘David believes that the PM is wise’, it is a sense.

Stefano Predelli - Spring 2009

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The intuitive aspects of Frege’s theory. When we say ‘David believes that the PM is wise’, we attribute a thought to David, the thought that the PM is wise. Thoughts are determined by sense. If we substitute expressions with different senses, we affect the thought Why David’s case is not a counter-example to compositionality of reference: ‘David believes that the PM is the husband of S’ ‘David believes that the PM is the PM’ do not differ only for co-referential expressions
Stefano Predelli - Spring 2009

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A simpler example: David sincerely assents to ‘the PM is wise’, but not to ‘the husband of Sarah is wise’ Then, ‘David believes that the PM is wise’ is true, but ‘David believes that the husband of Sarah is wise’ is false Unbeknownst to David, the PM is the husband of Sarah, i.e., ‘the PM’ and ‘the husband on Sarah’ are co-referential

Stefano Predelli - Spring 2009

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David

believes

that

the PM

is wise

S1 believing wisdom

S2

David

believes

that

the husband of S

is wise

Stefano Predelli - Spring 2009

The Hierarchy of Senses
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Recall Frege’s general insight: expressions have not only a reference but a sense Stronger (Frege?): referent is determined by sense the occurrence of ‘the PM’ in ‘David believes that the PM is wise’ has a referent (the sense of ‘the PM’) What is its sense? (Roughly) it must be the sense of ‘the sense of ‘the PM’’ Frege calls this the indirect sense of ‘the PM’

Stefano Predelli - Spring 2009

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the PM is wise

refers to Gordon (Gordon = customary referent of ‘the PM’)
expresses S (S = the customary sense of ‘the PM’)

David believes that the PM is wise refers to S (S = the customary sense of ‘the PM’ = the indirect referent of ‘the PM’ expresses S* (S* = the indirect sense of ‘the PM’)

Stefano Predelli - Spring 2009

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Intuitively (?), when we say ‘David believes that the PM is wise’, we are talking about David’s thought, and hence about David’s sense for ‘the PM’ (In the case of a description, presumably also our sense for ‘the PM’) But belief reports may be embedded: ‘David believes that the chancellor believes that the PM is wise’ Sloppily: we are talking about David’s sense for ‘the chancellor’, and David’s notion of the chancellor’s sense for ‘the PM’

Stefano Predelli - Spring 2009

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David believes that the chancellor believes that the PM is wise ref ref ref truthconditions

S1

S2*

det
S2

det det

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David believes that the chancellor believes that the PM is wise ref the referent for this doubly-embedded occurrence (the doubly indirect referent of ‘the PM’) = the indirect sense of ‘the PM’

S2*

the referent determined by the indirect sense of ‘the PM’ = the customary sense of ‘the PM’ = the indirect referent of ‘the PM’

det S2 det

the referent determined by the customary sense of ‘the PM’ = the customary referent of ‘the PM’

Stefano Predelli - Spring 2009

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In ‘David believes that the chancellor believes that the PM is wise’, ‘the PM’ refers to its indirect sense. So, what is the sense of this occurrence of ‘the PM’? It must be a sense that determines the indirect sense of ‘the PM’ Frege: the doubly-indirect sense of ‘the PM’ And so on (‘David believes that the chancellor believes that the queen believes that the PM is wise’, ...)

Stefano Predelli - Spring 2009

Frege on belief reports
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Some consequences of Frege’s view (1) a third role for sense: serve as indirect referent (2) ‘that’ as a reference-shifter (3) a hierarchy of senses (4) substitutivity of synonymous expressions. ‘Wayne believes that David’s lawyer is rich’ is true iff ‘Wayne believes that David’s attorney is rich’

Stefano Predelli - Spring 2009

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How about substitutivity of co-referential expressions? In a sense, it fails: pick two expressions that have the same referent (‘the PM’, ‘the husband of S’), you cannot substitute them salva veritate: ‘David believes that the PM is wise’ can be true, but ‘David believes that the husband of S is wise’ can be false. In another sense, it holds: in the case above, the occurrences of ‘the PM’ and ‘the husband of S’ are not co-referential, hence not a counter-example against sub

More from S&R
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(a) senses are not ideas – ideas are private psychological items, senses are public (shareable). Note: we may attach different senses to ‘Aristotle’, but we may also share that sense. ‘... one man can associate this sense and nother that sense. But ... they are not prevented from grasping the same sense’ (though ‘they cannot have the same idea’) Senses as abstract entities (the ‘third realm’)

Stefano Predelli - Spring 2009

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(b) further aspects of language: ‘colouring and shading’. E.g. (negotiable), ‘rabbit’ vs. ‘bunny’. (c) further comments on empty names, on the sense and reference of sentences (d) more on belief reports, and further considerations on ‘subordinate clauses’

Stefano Predelli - Spring 2009


								
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