Hmmm! I just read that Quine thing a few weeks ago, and I thought the two meanings were pretty much the same. It's something about the difference between the intension and the extension of "the morning star". The extension of the morning star includes the evening star, right? It also includes Venus, and "the planet next closest to the sun" and all sorts of other fact. But once we introduce intension in to the conversation, we no longer can assert that the morning and the evening star are the same, because the question is not about what they are, not what they mean to somebody. Now, I admit I read Quine over and over again without the question being quite settled in my mind, but that is where I ended up last time I thought about it.
Nick -----Original Message----- From: Friam [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, April 17, 2013 7:41 PM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] Tautologies and other forms of circular reasoning. > In my (leetle) world, referential opacity refers to ambiguities that > arise in intentional utterances ... utterances of the form, "Jones > believes (wants, thinks, hopes, etc.) that X is the case. " They are > opaque in that they tell us nothing about the truth of X. So, for > instance, "Jones believes that there are unicorns in central park" > tells us neither that such a thing as a horse with a horn in its > forehead exists (because Jones may confuse unicorns with squirrels) or > that there are any "unicorns" in central park, whatever Jones may > conceive them to be (because Jones may be misinformed). > > > > What does the computer community think "referential opacity" means. If they're at all like whatever community W. V. O. Quine belonged to (mathematical logicians? empiricist philosophers?), they think it means something quite other than what you wrote above. --Actually, all I know for sure is that what Quine meant by "opacity of reference" was quite incompatible with your meaning of "referential opacity". His standard example of "opacity of reference" was the pair of phrases "the morning star", "the evening star", both of which *in fact* refer to precisely the same celestial body, viz., Venus, although the facticity of that fact may be opaque to any given speaker of the two phrases. ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
