- From: John Cowan <cowan@ccil.org>
- Date: Fri, 14 Mar 2008 11:06:12 -0400
- To: Pat Hayes <phayes@ihmc.us>
- Cc: "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "www-tag@w3.org" <www-tag@w3.org>
Pat Hayes scripsit: > Well, this illustrates the problem, seems to me. Suppose I accept > your claim that your URI denotes the moon, so that when I use it I am > also referring to the same moon. But I want to point out that you > said something false about the moon. Under your proposal, this is > impossible. I can't say that, because by calling these assertions a > 'declaration', they have been removed from the domain of discussion. So they have, but that's unavoidable. If we take the predicates "is a natural body", "orbits the Earth", and one more that I can't formulate exactly but is meant to exclude captured meteoroids if any there be, then these *define* the moon. If you contradict any of them, you are not talking about the moon any more. (Another basis system could be given, such "occupied point P at time T" for appropriate choices of space and time scales; it matters not.) Note that none of these are essential properties in the Kripkean sense I was using before; essential properties are not necessary as long as we confine ourselves to the actual world and don't worry about contrafactual worlds. However, once the moon is properly defined (= distinguished from all other objects to the extent possible or required), I can then make any number of assertions about it, any of which you may contradict, of course. > Why should it be that by using a name correctly, given your > intentions for using it, that I must therefore agree with everything > you say about it? Not everything, only the assertions in the declaration (of identity). -- What has four pairs of pants, lives John Cowan in Philadelphia, and it never rains http://www.ccil.org/~cowan but it pours? cowan@ccil.org --Rufus T. Firefly
Received on Friday, 14 March 2008 15:06:54 UTC