Is two-Dimensionalism just a new descriptionialist theory of names? (Part 1)

I have been trying to figure out whether two Dimensionalism is just a new descriptionalist account of names which Soames (2005) Byrne, and Pryor (2004) and others claim that it is. If that is the case then two Dimensionalism suffers from the same Marcuian/Kripkean style arguments against descriptionalism.

Basically, descriptionalists maintain that names are disguised descriptions so the name Shakespeare refers to some set of conjunctive descriptive properties (English playwright and author of Macbeth and knighted by Queen Elizabeth I, etc.). Marcus and Kripke deny this claim and instead claim that names function as tags or rigid designators. Names pick out the object they are referring to. Marcus and Kripke appeared to have shown that the descriptionalist account of names is untenable. There also seems to be a general acceptance that Marcus and Kripke were right about that. Two-dimensionalism (as far as I can tell) came along in response to the problem that indexicals pose for this new theory of reference and the intuition that there is some sense in which the contingent a priori is still necessary and in some sense the necessary a posteriori is still contingent.

One of the intuitive scenarios that support the employment of 2D semantics was told to me by Dr. Janice Dowell and then later by Frank Jackson.

Kripke argued that it is a necessary a posteriori truth that water = H2O. Through science it was discovered that water is H2O. If we take identity to be necessary then we discovered something necessary in the world through a posteriori research. Given what it is for something to be a necessary truth, something that is true in all possible worlds, there are no worlds where water isn’t H2O. Water can’t be something like XYZ.

Now the Jackson scenario. Suppose tomorrow that we open a well respected scientific journal and it reads “Water is not really H2O it is XYZ. Some companies bribed the original scientists who discovered that water is XYZ to report that water is H2O.” The intuitive pull from that claim is that if we consider such a world as actual then it doesn’t necessarily follow that water is H2O. This is what Chalmers (2007 and else where) has called an epistemic possibility. It is epistemically possible for water not to be H2O because it can’t be ruled out on a priori grounds.

A Yablo response to Chalmers’ Two-Dimensional framework

I am currently going over an example presented by Yablo (2002). Yablo’s take of the a priori seems to take a very minimal view of what it means for a proposition to be an a priori truth. At best, an a priori truth is something like ‘a = a’ or ‘’sister’ means sister’. What Yablo denies is that ‘’sister’ means female sibling’ is a priori which appears very counter-intuitve and I will get to why Yablo thinks this very soon. Lastly, Yablo denies that there are no contingent a priori truths which runs counter to Kripke.

The way Chalmers (2007) reads Yablo is ”Yablo (2002) suggests that certain disquotational truths, such as “’sister’ means sister”, are a priori but are not 1-necessary.” Chalmers divides necessity into two types, strong necessity (1-necessity) and weak necessity (2-necessity). In order to understand this divison some other notions have to be introduced, primary intension and secondary intension. These different ’senses’ of intension can really only be given in terms of examples. The example is ‘It could be the case that Water is not H2O’ where that proposition appears to be a possibility but after Kripke we know that it isn’t. The fact that people at one time thought it was a possibility or that one can think of it as a possibility before reading Kripke tells us that ‘It could be the case that Water is not H2O’ primary intension is true. What Kripke’s work shows us is that ‘It could be the case that Water is not H2O’ is not really possible so the secondary intension is false. Notice that since the primary intension of “It could be the case that water is not H2O,” is true then “Water is H2O” comes out as a contingent truth but its secondary intension is a necessary truth. A priori propositions like “2+2=4″ or “a = a” are ones whose primary and secondary intension come out true. With that in mind we can describe weak and strong necessity.

If you have a proposition that has a weak necessity then that proposition only comes out true under its secondary intension. This means that the proposition “Water is H2O” primary intension is only contingently true so that proposition is only weakly necessary. Propositions like “a = a” and “2+2=4″ have a true primary and secondary intension so they have a strong necessity.

Now we can look at Yablo’s objection. Yablo claims that (1) ‘’sister’ means sister’ is an a priori truth while (2) ‘’sister’ means female sibling’ is not an a priori truth. If that is the case then (1) is not 1-necessary under Chalmers’ framework since ’sister’ could mean something different. You could have a world where ’sister’ means cat so in that world ’sister’ does not mean sister in our world.