This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.
Dear Dr. Craig,
I was listening to an older podcast of yours wherein you stated that one can affirm states of affairs without needing to affirm the truth-status of the proposition used in the affirmation of any state.
However, if we deny the reality of truth-status' (in an effort to avoid making propositions or "truth" a real, existing thing), then how can one say that any proposition is self-refuting?
For example, if I say that, "There are no true claims at all." How could you point out the self-refuting nature of the proposition without addressing the truth-status of the propositional claim itself?
I guess I'm having difficulty understanding your desire to avoid semantic "truth" talk, and it appears simply to be a way to prop up your nominalism. While I think it's perfectly reasonable to adopt ways of viewing things which are consistent with our beliefs (and well all obviously do that), it seems that your desire to hold to nominalism requires that your give up too much, especially as a Christian who is supposed to affirm Biblical notions like "truth", which Jesus Himself affirmed.
For the record, I find your criteria for existence appealing, since it avoids an infinite regress which plagues a property-possessing view of existence. However, while it has that advantage, I still find a conceptualist view of abstractions to be overwhelmingly intuitive, so I'm still searching for a criteria for existence which can maintain abstractions while avoiding an infinite regress.
Thanks for your work and all you do to further the cause of Christ.
Dr. William Lane Craig’s Response
Hold on, Frank! I think you’ve misunderstood me. Please take a look at my article “Propositional Truth: Who Needs It?” “Propositional Truth: Who Needs It?” Philosophia Christi 15 (2013): 355-64 15 (2013): 355-64 for a fuller exposition of my view.
You’re quite right in thinking that my anti-realism about abstract objects, including propositions, is theologically motivated. As a Christian philosopher, I follow Alvin Plantinga’s “Advice to Christian Philosophers” to think integratively about the philosophical questions we face. We should look at the world from the perspective of what we know about God and what He has revealed to us. Hence, I think that theological objections to any given view are just as important, and sometimes more important, than philosophical objections to that view.
So if I thought that Jesus’ teachings about truth committed us to the reality of propositions or properties, I would take that very seriously, indeed. But when Jesus said, for example, “I am the truth,” he was not speaking philosophically but metaphorically. He obviously did not think that he was a propositional property or truth value!
The Judaeo-Christian doctrines of divine aseity and creatio ex nihilo, on the other hand, require us to affirm that God is the sole ultimate reality, that no uncreated things exist apart from God Himself. That rules out Platonism with respect to the existence of things like propositions, properties, numbers, possible worlds, and so on.
In the article referenced above, I explain that anti-realism about such entities does not preclude our talking as if such things existed. The philosopher Rudolph Carnap made a helpful distinction between claims made within a linguistic framework and claims made outside of that framework. Suppose, for example, that I choose to adopt the linguistic framework of talk of properties. Claims made within that framework like “The dog has the property of brownness” or “John has the property of attending the University of Notre Dame” are unobjectionable. Such property talk is a great convenience and can avoid cumbersome circumlocutions that might be necessary to avoid it. But it need not be taken as ontologically committing to the reality of properties.
The question as to whether properties really exist is an external question, posed outside the framework. Speaking externally, the anti-realist will say that properties do not exist and that, therefore, the dog does not have the property of brownness, even though the dog is brown, nor does John have the property of attending the University of Notre Dame, even though he attends the University of Notre Dame. Property talk is just a useful façon de parler.
Similarly, we may adopt the linguistic framework of talk of propositions. Internal to such a framework, it is unproblematic to talk about various propositions’ being true or false. Someone who asserts within this framework the proposition There are no true propositions at all is making a self-defeating claim because he takes that proposition to be true. I take this to be sufficient for the self-refuting nature of the claim you mention. Such a person has adopted the linguistic framework of talking of propositions and then asserted a self-referentially incoherent claim.
But for someone standing outside the framework, he may wonder whether abstract objects like propositions really exist. The anti-realist will say that there are no propositions. Therefore, there are no true (or false) propositions either. Made outside the framework, such a claim is perfectly coherent. When I say external to the framework that “There are no true propositions,” I am not making the self-defeating claim that the proposition There are no true propositions is true. From my vantage point outside the framework, rather than assert that p is true, I just descend semantically and assert that p.
For example, rather than making the internal claim that “It is true that Sherrie loves chocolate,” we can descend semantically and just say, “Sherrie loves chocolate.” When we say that, we speak truly just in case Sherrie loves chocolate, but we speak falsely if she does not. So we can still speak truly or falsely regardless of the existence of abstract propositions. Someone external to the framework who says “There are no propositions” speaks truly because there are no propositions. That does not imply any kind of weirdo post-modernist anti-objectivism or relativism.
When we say “It is true that Sherrie loves chocolate,” we have ascended semantically, so that we are no longer talking about Sherrie but about a proposition instead. Why is a device of semantic ascent useful or needed in natural language? The answer is that the truth-predicate serves the purpose of blind truth ascriptions. In many cases we find ourselves unable to assert the proposition or propositions said to be true because there are too many of them, as in “Everything he said was true,” or because we are ignorant of the relevant propositions, as in “Everything stated in the classified documents is true.” We need a device of semantic ascent to make such blind truth ascriptions. So, far from seeking to “avoid semantic ‘truth’ talk,” I think such talk is indispensable for human discourse. When we cannot make the relevant assertions, we need a device of semantic ascent in order to say what we want to.
Finally, Frank, I am not averse to your own solution of divine conceptualism. Perhaps the anti-Platonist can avoid abstract objects by substituting God’s thoughts for propositions as the bearers of truth value. What I cannot accept is that there exist uncreated abstract objects independent of God.
This post and other resources are available on Dr. William Lane Craig's website: www.reasonablefaith.org