Friday, September 10, 2010

objects of attitudes & modal operators: king's criticism of richard

Jeffery King 2003 criticizes Mark Richard's 1982 semantics for attitudes reports and tense and modal operators. King's criticism is the following:

One problem with Richard's account is that since tense and modal operators operate on the same thing, since these are not propositions and since propositions are the objects of the attitudes, for Richard the objects of the attitudes and the things modal operators operate on are not the same. But that means that on Richard's view, the following inference should not be valid...But this inference certainly does seem valid:

(i) Shannon believes that God exists,
(ii) It is possible that God exists,
(iii) Therefore, Shannon believes something that is possibly true.

Such arguments leave me completely unmoved, since there has been no actual demonstration that the argument is not valid according to Richard's semantics?
Show me the semantics! It seems that if we do crunch through a semantics according to which the objects of the attitudes and the things modal operators operate on are not the same, the argument actually comes out as valid.

In order to assess the validity of this argument we need to know what the logical form and semantics of the premises are -- especially premise (iii). We might analyze `Shannon believes something' as `There is something that Shannon believes'. Let's give that the following semantics: [[∃q(Believes(Shannon, q)]]^{c,w,t} = 1 iff there is a q such that BEL(Shannon, q). Importantly, here we need not assume that the things that individuals stand in the BEL relation to are propositions -- they can be non-propositional semantic values of some sort. This in no way commits one to the claim that the objects of belief are non-propositional semantic values. It is completely consistent to say that `Shannon believes something' is true just in case there is a semantic value q that is
so-and so, while at the same time maintaining that the the things we believe are propositions. That is why it is not enough to just allude to a problem here without actually looking at the details of the semantics. If we tack on the conjunct about possibility we get the logical form of (iii): [∃q(Believes(Shannon, q) & Poss(q)]. From here is follows fairly straightforwardly that (i) [Believes(Shannon, G)] and (ii) [Poss(G)] entail (iii) by conjunction introduction and existential quantification.

Have I missed something?

J. King. (2003). Tense, modality, and semantic values. Philosophical Perspectives, 17(1):195–246.

M. Richard. (1982). Tense, propositions, and meanings. Philosophical Studies, 41(3):337–351.

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