3

According to Quine, the following sentence is literally nonsense:

∃x (Ralph believes that x is a spy)

Question: Exactly how does the sentence above devolve into non-sense according to Quine?

EDIT: Here is my understanding of Quine's argument. It's set in the context in which Ralph suspects that the man in the brown hat is a spy, and yet doesn't suspect that the mayor of his town is a spy. Under this scenario, we suppose that the man in the brown hat and the mayor of Ralph's town are in fact the same person.

Quine's Rejection of Quantification into Propositional Attitudes.

  1. Consider the two sentences:

    (1) ∃x(Ralph saw x wearing a brown hat and Ralph believes that x is a spy)

    (2) ∃x(x is the grey-haired mayor of Ralph's town and Ralph does not believe that x is a spy)

  2. Existential quantification has an objectual reading: (1) and (2) are true iff there exists an actual object (i.e., a man) that satisfices (1) and (2).

  3. The only man which satisfies (1) and (2) is Ortcutt.

  4. But the term Ortcutt has several different names: "Ortcutt", "the mayor of Ralph's town", "the man in the brown hat", and so forth.

  5. Hence (1) and (2) are true, and seem to imply (absurdly) all of the following:

    "Ralph believes that Ortcutt is a spy."

    "Ralph does not believe that Ortcutt is a spy."

    "Ralph believes that the mayor of his town is a spy."

    "Ralph believes that the man in the brown hat is not a spy."

  6. Hence quantification into propositional attitudes is deemed "nonsense".

Is this Quine's position in a nutshell?

  • Yes; see page 179 : Quine says that for belief-1, the case (7) : (∃x)( Ralph believes that x is a spy) is nonsense because the "belief" term is niside the scope of the quantifier, and this produces ambiguities. Thus, I think, he call it "nonsense" because he propose a "formalization" of belied contexts in which quantification as (7) are not allowed. – Mauro ALLEGRANZA Oct 22 '14 at 8:05
6

See W.V.Quine, QUANTIFIERS AND PROPOSITIONAL ATTITUDES, in THE JOURNAL OF PHILOSOPHY (1956).

"Belief" contexts are "intensional" ones, and Quine does not "like" them because they have no satisfactory analysis in term of first-order logic.

A phrase like :

"Ralph believes that someone is a spy"

is ambiguous (I don not think that he says : "meaningless") because it can be analyzed in two ways; as :

(∃x) (Ralph believes that x is a spy),

and as :

Ralph believes that (∃x) (x is a spy).

  • He goes onto argue in that essay that the middle sentence is literally non-sense (and as such belief statements don't literally pose scope ambiguities of the type described here). I'm trying to understand why he thinks the second sentence is devoid of meaning. – George Oct 21 '14 at 15:56
1

The standard reconstruction of Quine's somewhat opaque argument can be found in David Kaplan's wonderful piece "Opacity", published in The Philosophy of W.V. Quine. Open Court 1986. In what follows I'll give a somewhat condensed version of it.

Let A(x) be some open sentence, where at most the variable 'x' occurs free. Let the position(s) occupied by 'x' in A(x) be opaque, if for any term t the truth of A(t) depends on the way the denotation of t is described.

Here comes Quine's argument a'la Kaplan:

P1. The sentences 'Ralph believes that Ortcutt is a spy' and 'Ralph believes that the man in the brown hat is a spy' have different truth conditions.

P2. If there are coreferential terms t, t' such that A(t) and A(t') have different truth conditions, then the position occupied by 'x' in A(x) is opaque.

P3. If the position occupied by 'x' in A(x) is opaque, then the sentence ∃xA(x) cannot be assigned any interpretation, i.e. it is 'meaningless'.

I think that P1 and P3 are OK. However, P2 is surely false; but that is another story, as you asked for Quine's argument and not for an evaluation of it.

  • Do you have a link to Kaplan's paper? – George Oct 23 '14 at 4:45
  • If not, what motivates (P3)? – George Oct 23 '14 at 4:46
  • No. P3 is motiviated by quotation and logophoric expressions ("so-called" etc.): ""Plato" contains six letters" depends for its truth on how Plato is described and the same is true for "Plato is so-called because of his size". And "∃x("x" contains six letters)" as well as "∃x(x is so-called because of the size of x)" are instances of non-sense. – sequitur Oct 23 '14 at 23:05
0

There is a deeper way in which all "modal" constructs are meaningless propositionally. If I inject a 'should' into a perfectly reasonable proposition, I am positing a system of values that I cannot articulate. Likewise 'would' refers to some frame of mind, 'might' refers to some potentially-alternative reality (or to this one, and no one can tell).

Having mood other than the indicative insulates the proposition from validation. Such statements do not intend to convey meaning, they imply judgement, raise uncertainty, emphasize power-leverage... or otherwise tune a number of other variables only partially related to truth.

Belief is modal. I cannot know that Ralph believes something because he said so. I cannot know he believes it because he has all the information needed to imply it. Even he often cannot tell whether he believes it until he reaches a point of action that involves applying it, and then he may only believe it is the best likelihood. Belief has some continuous value with multiple dimensions, and cannot be reduced to a proposition with truth-values.

(But in this sense, both versions mentioned in the passage referenced are equally meaningless to quantify over. So I think the two answers so far fall wide of your mark on both sides.)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.