[Top] [All Lists]

[ontolog-forum] what is a proposition?

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Ingvar Johansson <ingvar.johansson@xxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 23 May 2007 09:23:53 +0200
Message-id: <4653EC09.8020005@xxxxxxxxxxxxxxxxxxxxxx>
Dear John and all others interested,    (01)

I would like to switch from "truth and reality" to "what is a 
proposition?" Here is what one of my philosophical dictionaries says:    (02)

"In philosophy, but not in business and sexual activity, a proposition 
is whatever can be asserted, denied, contended, maintained, assumed, 
supported, implied, or presupposed. It is that which is expressed by a 
typical indicative sentence. The same proposition may be expressed by 
different sentences."    (03)

John F. Sowa schrieb (but italics mine, IJ):
> But I would like to restate
> them in terms of propositions, although the word 'proposition' is
> also considered to be in some *need of clarification*.  The definition
> of proposition that *I prefer* is one I stated in
>     http://www.jfsowa.com/logic/proposit.htm
> The basic idea is summarized in the abstract of that paper:
>     Informally, different statements in different languages may mean
>     "the same thing." Formally, that "thing," called a proposition,
>     represents abstract, language-independent, semantic content.
>     As an abstraction, a proposition has no physical embodiment that
>     can be written or spoken. Only its statements in particular
>     languages can be expressed as strings of symbols. To bring the
>     informal notion of proposition within the scope of formal treatment,
>     this paper proposes a formal definition:  a proposition is defined
>     as *an equivalence class of sentences in some formal language* L
>     under some meaning-preserving translation (MPT) defined over the
>     sentences of L. This paper defines a series of six MPTs f0,...,f5
>     and recommends f4 as the most useful for most purposes.
>       (04)

I have read your paper, understood (I think) your constructions, and 
have no objections to your views - apart from the fact that I find it a 
misnomer to call any of your six constructions a definition of 
"proposition". Earlier in the discussion, I got the impression that both 
of us were of the opinion that propositions are the primary truth-value 
bearers, but "an equivalence class of sentences in a formal language" 
cannot be a truth-value bearer. I have noted that you call your 
definition a "formal definition" of proposition, but I  think a more 
adequate label would be "definition of the formal-logical counterpart to 
propositions". You exemplify with FOL, but I wouldn't say that sentences 
in FOL are truth-value bearers; they are forms for truth-value bearers. 
That is, you bring out something in your paper, but you do not, as you 
claim, *clarify* the traditional philosophical concept of "proposition".    (05)

What do you (or someone else) say?
Ingvar    (06)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (07)

<Prev in Thread] Current Thread [Next in Thread>