Monday, July 18, 2005

The argument from Truth

Carrier’s account of truth is indeed a correspondence theory of truth. He writes:
From an analysis of data a brain computes varying degrees of confidence that a virtual model does or does not correspond to a real system. If there is such a correspondence, then having confidence in this is a true belief, while having confidence that there isn't such a correspondence would then be a false belief. If there is no such correspondence between the virtual model and reality, then having confidence that there is such a correspondence is a false belief, but having confidence that there isn't such a correspondence would be a true belief. Thus, Proposition 2 only requires the existence of correspondence and confidence, both of which can and do exist on naturalism.

But there is a problem with this whole idea. If truth is a relationship between someone’s belief that something is so and the reality that it is so, then what that means “there is at least one reptile” would not have been a truth during the Jurassic period, unless there was someone in existence during the Jurassic period who had confidence that his or her thought corresponded to the truth “there is at least one reptile.” (I owe this point to Bill Vallicella). And unless there is something like a God, we do not know of anything alive during that time that had confidence in the representation, “There is at least one reptile alive now.”

Because of this, a naturalist may be inclined to accept the idea what can be true or false are not states of the person but propositions. These propositions could exist timelessly, but not exist in anyone’s mind. If that were the case then the proposition “There is at least one reptile alive during the Jurassic period” would be a truth that would exist at that time, because it would be true at all times.

This account of propositions is hard to square with some versions of naturalism, according to which everything that exists exists at some place and time in particular. But if we waive this requirement, there are still difficulties. In particular the argument from reason based on mental causation maintains that naturalism cannot explain how one thought can cause another thought in virtue of its content. On this view, how would it be possible for our thought to be related to the truth that our thoughts are about, if our thoughts are completely products of the spatio-temporal-physical world, but the truth of our thought does not exist in any particular place or time. The physical, is supposed to be causally closed according to naturalism, and as such nothing outside the physical, whether eternal propositions, or nonphysical souls, can affect what goes on in the physical world. Because of this, I regard this move to non-spatial propositions as the acceptance of a poisoned pawn, the taking of which will make the next argument, the argument from mental causation, impossible to answer.

4 comments:

Giordano Sagredo said...


But there is a problem with this whole idea. If truth is a relationship between someone’s belief that something is so and the reality that it is so, then what that means “there is at least one reptile” would not have been a truth during the Jurassic period, unless there was someone in existence during the Jurassic period who had confidence that his or her thought corresponded to the truth “there is at least one reptile.” (I owe this point to Bill Vallicella).


This doesn't resonate at all with me as a problem. If truth/falsity is a property of beliefs (say I stipulate that is how I am using true/false, then Valicella would say it is "the mark of a bonehead" to disagree with me). Since there were no beliefs back then, then the semantic properties of being 'true' or 'false' did not yet exist, in much the same way the property of being a human did not exist. What is the big deal?

My guess is that part of the power of this intuition is the condescending sneer that you might be able to muster when you retort, "So, it was FALSE that there were reptiles back then?!", which, while perhaps scoring some rhetorical points, would be to miss the point entirely. Someone might as well claim incredulity when I find fault with the claim, "It is 2005, and Abe Lincoln is riding a bicycle."

Clearly, I believe that there were reptiles during the Jurassic period, and the features of the world that determine the truth/falsity of this proposition are the same whether or not I believe it. So, yes, there were reptiles back then, but no, nobody had that thought. My present thought has the property of being true in virtue of the fact that the physical world was structured a certain way in the past, but the semantic properties of being true and false did not yet exist.

When someone says, "It was true, during the Jurassic period, that there were reptiles", I look at this as a redundant way of saying "During the Jurassic period, there were reptiles." It is a claim about the state of the world during the Jurassic, not about the state of some abstract proposition that existed back then. If someone insisted that the latter is what they meant, then I would ask them to clarify their notion of 'truth', and to what kinds of objects this property belongs. I wonder which analysis would look more incredible when both were more clearly on the table.

Victor Reppert said...

I did have a discussion of the correspondence theory of truth ina previous post, which in my paper immediately precedes this discussion.

Giordano Sagredo said...

I was attacking the supposed preposterousness claimed by Vallicella of a particular species of the correspondence theory of truth (a species I tend to believe in).

Truth is a property of certain cognitive/linguistic structures, and what makes these structures true (or false) is the state of the world. To bumpersticker my view, there existed truth conditions before there existed truth. There were reptiles before there were propositions such as 'There are reptiles.'

For someone wanting to find problems with this view, they should attack me on mathematical/logical truths such as '1+1=2'. Unlike claims about reptiles, it is not clear that the truth conditions for such claims did not exist before humans existed.

What are the truth conditions for '1+1=2'? I tend to be a pragmatist/quinian: 1+1=2 is just another empirical hypothesis, but one that is very general and applicable to a wide range of phenomena. However, it doesn't work well to describe water droplets (when I combine two droplets I get one droplet!).

At any rate, math is the place to attack me, and the previous paragraph describes my general Quinian strategy.

Giordano Sagredo said...

I said:
Unlike claims about reptiles, it is not clear that the truth conditions for such claims did not exist before humans existed.

I meant to say that it is not clear that the truth conditions did exist before humans existed. The rest of what I said follows from this puzzle...