Monday, November 03, 2008

Against Legal Dialetheism

Priest presents the following case for Dialetheism in his book In Contradiction: Suppose that there is a country that has a legislative body that passes a law saying that all land owners are legally permitted to vote and another law that says that no women are legally permitted to vote. We might also suppose that at the time these laws were passed the legislature also passed a law barring women from owning land, but that this last law was eventually repealed. Now, given that there is now no ban on women owning property, we might suppose that a woman, Bridget, buys a piece of land. But, it seems to follow from the first two laws that Bridget is legally permitted to vote and it is not the case that Bridget is legally permitted to vote. so, if this scenereo is a possible scenario, then it looks like it is possible for a contradiction to be true. This seems unacceptable though.

Let's try to make the argument more precise. It seems that all of the following propositions might jointly be true.

1. A legislature governing state S passes a law that says that all land owners are legally permitted to vote in S.
2. If (1), then all land owners are legally permitted to vote in S
3. A Legislature governing state S passes a law that says that no women are legally permitted to vote in S.
4. If (3), then no women are legally permitted to vote in S.
5. Bridget is a women who owns some land.
6. So, Bridget is legally permitted to vote in S and it is not the case that Bridget is legally permitted to vote in S.

It seems that statements (1)-(5) are jointly possibly true. So, it seems that statement (6) is possibly true as well. However, (6) is not possibly true. The puzzle for anyone who objects to (6) is to give an informative explanation of why (1)-(5) are not jointly possibly true.

I take it that all the action is in premises (2) and (4). But, these premises seem to simply embody the fact that legislatures have the power to make certain things true. they can make certain truths about what is legally permitted and what is not. It is important to note that (2) and (4) are not justified by some general principle that says legislatures can make anything true. That would be silly, legislatures obviously can't make it true that my hand is green. Moreover, they are not justified by some general principle that says legislatures can make any claim involving legal permissibility true. If this latter view were true, then legislatures could make contradictory legal statements true. Rather (2) and (4) are justified by the intuitive claim that a legislature can make these particular claims true. These claims are consistent with one another and it seems plausible that a legislature might make both of them true along with a third law that says no woman is legally permitted to own land. Once that third law is repealed, it might very well be the case that Bridget purchases some land and (5) becomes true.

I want to give a plausible view according to which either (2) or (4) is false. The plausible view is as follows. Either the legislature governing state S cannot make it so that no women are legally permitted to vote in S or they cannot make it so that all land owners are legally permitted to vote in S. Rather, they can definitely make the following true:

(a) According to laws L of S, all land owners are legally permitted to vote.

and

(b) According to laws L of S, no women are legally permitted to vote.


No contradiction follows from the combination of (a) and (b) along with the fact that Bridget is a woman who owns land. Rather, it simply follows that according to the laws of S, Bridget is legally permitted to vote and according to the laws of S, it is not the case that Bridget is legally permitted to vote.

On this view, we think that (2) and (4) are true because the legislature of S can make (a) and (b) true. Moreover, we often say that land owners are legally permitted to vote or that no women are legally permitted to vote, when we intend to convey the truths expressed by (a) and (b).

As for the literal truth or falsity of (2) and (4), I guess I am not sure what to say. However, I think that most people would be happy to say that the sentences used to express (2) and (4) are context sensitive and that they they really express (in this context) conditionals with (a) and (b) in their consequents. I am against the context sensitivity claim and think there is something literally expressed by (2) and (4) that is different from what the contextualist thinks might be expressed by (2) and (4) in the appropriate context. But, I don't know enough about what is expressed to know which of (2) or (4) is false.