But, it's the same individual due to his descriptive content. — Wallows

No, it isn't. The description is not a rigid designator.

In some possible world, Wallows is a a fat plump man living at the North Pole, who knows whether you've been a good or bad, and rewards accordingly with coal or presents.

See?

The description is not a rigid designator. — Banno

Going back to the example of the meter-stick, the length of the meter stick is the definite description, not the meter stick itself.

Anyway, what I've seen going on in the other thread is the matter of placing the horse behind the cart. Namely, if we are to talk about rigid designators, then it seems to me that the description of it is what guarantees its rigidity in possible worlds where they obtain.

@Wallows

Let's go over the Barcan formula.

(x) □ɸ(x) ⊃ □(x)ɸ(x)

If: everything necessarily has a particular property.

Then: necessarily, everything has that particular property.

Accepting this means that we cannot stipulate things that are not already in this world, because that would allow us to stipulate things that did not have the property ɸ.

But we can stipulate things that are not already in this world.

So there are things we can do in English that are ruled out by the Barcan formula. Hence, logics which include the Barcan formula cannot parse some sentences of English.

This does not bring unstipulated beings into existence, though... Does it?

Compare this thread: All A is B and all A is C, therefore some B is C, where things are said to appear in a puff of logic.

Going back to the example of the meter-stick, the length of the meter stick is the definite description, not the meter stick itself. — Wallows

Hm. The length of the metre is rigidly designated by the name "metre". "The length of this stick" is a definite description. Keep the quotes in, to show we are talking about the words, and not the length of the stick.

So there are things we can do in English that are ruled out by the Barcan formula. Hence, logics which include the Barcan formula cannot parse some sentences of English. — Banno

If you want to take a hard reading of the Barcan Formula, then the stuff that is beyond the scope of the Barcan Formula, are known unknowns or metaphysics if you will. Did I mention that the Barcan Formula applies to The Simplest Quantified Modal Logic?

Compare this thread: All A is B and all A is C, therefore some B is C, where things are said to appear in a puff of logic. — Banno

Yeah, and the Barcan Formula eliminates such confusions with asserting properties that exist and can be stipulated, not properties belonging to the realm of stuff existing in Meinong's Jungle or Plato's Beard.

The Barcan Formula is what Occam's Razer is to quantified modal logic.

:grin:

Hm. The length of the metre is rigidly designated by the name "metre". "The length of this stick" is a definite description. Keep the quotes in, to show we are talking about the words, and not the length of the stick. — Banno

I propose that "the length of this stick" attains its meaning from the fact that a meter is defined as the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second. A second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

So, a "meter" is the same as the definite description that is empirically true in any possible world where the above relations are the same or "actualized" as in the actual world where they obtain.