Wednesday, October 8, 2008

Worry, yes. Insight? Maybe.

I had a bit of a crisis of faith over propositions this morning, and a resolution. I thought I'd share. Were the worries worth the worry? Is the solution satisfactory?

I began by considering:

(A) Dan is a philosophy student.

(B) Dan-eun chul-hak saeng-ibnida.

I thought that it was a mistake to assume:

(1) If A in L1 translates into B in L2, then A expresses the same proposition that B expresses.


(C) Gutentage.


(D) Bonjour.

and neither (C) or (D) expresses a proposition.

Perhaps (1) could be amended:

(2) If A in L1 translates B in L2, and if A and B both express propositions, then A expresses the proposition that B does.

But given some reasonable assumptions (like Frege) we might feel that (A) and (B) express different propositions, even if the sentences and their propositions play the same sort of functional role. I was tempted to think that (A) and (B) were equal expressions but not identical; and so with the propositions expressed.

I worried that this would make propositions into wheels idly turning.

(E) Wes is a bachelor.


(F) Wes is unmarried.

both presumably 'mean' or 'say' the same thing (in the sense of 'equality') without 'meaning' or 'saying' the same thing (in the sense of 'identity').

But this strikes me as queer. How could distinct token-classes of the same type, like (A) and (B) .or. (E) and (F), express distinct propositions? Shouldn't we tie propositions to types and not token-classes?

It seems more plausible to reason:

1. (A) and (B) are of the same type.
2. Token-classes of the same type express the same proposition.
3. (A) and (B) express the same proposition.


4. (E) and (F) are distinct token-classes.
5. Distinct token-classes express distinct propositions.
6. (E) and (F) express distinct propositions.

It seems a Sellarsean move helps. Let us picture the state of affairs that it rains thusly:

(G) 〪〭〫〬

This will stand for the state of affairs that it rains, in a 'minimally linguistic manner'. We could imagine an ostensive definition instead, a scientific model of rain, etc. But we can explicitly put this state of affairs into language:

(H) It rains.


(I) Es regnet.

We can say that (H) and (I) are distinct token-classes of the •it rains• type. And the •it rains• type encodes (G).

It seems reasonable to conclude:

7. In the case of (A) and (B), (C) and (D), (E) and (F), and of (H) and (I), there are two sentences of distinct token-classes, but of the same type.
8. We can translate the sentence A in L1 into the sentence B in L2 iff A in L1 and B in L2 are of the same type.
9. If A translates B, then A and B are different ways of saying the same thing.
10. So (A) is a different way to say (B), (C) is a different way to say (D), (E) is a different way to say (F), and (H) is a different way to say (I).

What do (A) and (B) both say? They both encode, say, the same type. So (C) encodes •good day• and so does (D). On top of this translation principle, it seems we can note that some types encode states of affairs. So (C) translates (D) but they express nothing. They say the same thing but encode nothing. (Or not a state of affairs in any case.) But (H) and (I) are both of the same type; and this type encodes the state of affairs that it rains. Thus we might rewrite (2):

(3) If A in L1 translates B in L2, then A in L1 and B in L2 are of the same type. If a type expresses a proposition, then all tokens of token-classes of that type expresses that proposition.

Thus I satisfied myself and ended my worry.

I will lastly note:

11. That it rains is a state of affairs.
12. States of affairs can be encoded in language as propositions, or can be actualized in the world as facts.
13. If it rains is a fact, then •It rains• is true.
14. If it rains is not a fact, then •it rains• is false.

So it seems we get a nice little correspondence theory of truth, flush with propositions, facts, states of affairs, sentence-types, and translation rules. Yay!

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