Proofs, Persuasion and the Truth Problem
November 21, 2014
As a reminder of where we've been thus far, it might be helpful to list the Ten Tenets again. The Ten Tenets are these:
This month, we want to provide an explanation of Tenet 9.
In much of the history of apologetics, the notion of proof has been central. A defense of the faith, so it goes, is given when one gives a proof, or proofs, for the existence of a god. Once the proof is given, the apologetic task is done, and it might be prudent for the apologist to introduce his interlocutor to his pastor so that the central details of who this god is might be discussed.
Surely, the notion of proof in apologetics is important. We are called to provide reasons for the hope that is in us (1 Peter 3:15), and providing reasons can include mounting an argument. So, it is right and proper for us to think carefully about how we might prove the existence of God.
But we need to be aware that the notion of proof itself is not as straightforward as it might initially seem. We've mentioned this before, but it is worth a reminder. Take, as one example, a standard syllogism, consisting of two premises and a conclusion:
This syllogistic proof might seem utterly noncontroversial. But it's important for us to remember the proper way to think about arguments. Technically, arguments are neither true nor false; propositions are. Arguments are categorized as valid/invalid or sound/unsound. So, the first question to ask about the argument above is, "Is it valid?" The answer is yes. But we need to recognize what we mean when we say that an argument is valid. A valid argument is one in which if the premises are true, the conclusion necessarily follows. So, if the premises above are true, the conclusion is inescapable.
The next, more complex and controversial, question that must be asked about any argument is, "Is it sound?" A sound argument is a valid argument whose premises are agreed to be true. So, the next question to ask about the argument above is whether or not the premises are true? Is it true that "All men are mortal?"
Our intuitive response to that question is "Yes." But then we might pause for a moment and think about that response. Is it the case the every single person who has ever existed has died? Once we ask this question we are drawn inevitably into the knotty "problem of knowledge" that has plagued philosophy since its inception. The question of the truth of Premise 1 moves us to a further question: "How do we know that Premise 1 is true (or false)?"
For the sake of simplicity, let's say that there are basically two ways to ascertain the truth of Premise 1. The first way would be to see if there are any rational laws of thought that would require that Premise 1 be true. Is it a truth that we could know simply by virtue of the way we all think, without any reference to experience? The obvious answer is no. We wouldn't know what "men" are or what "mortality" is without our experience of them. So, since the truth of it requires our experience, and since its truth is dependent on its universal ("All men...") quality, the next question we ask is whether our experience is sufficient to allow us to affirm the truth of Premise 1. More simply, have we been able to know the status of all men so that we can affirm universal mortality? And now we're in a bind. No one has knowledge of the status of all men. The best we're able to do, therefore, with this syllogism is ascribe to it some degree of probability.
If you are a Christian, you might have thought about someone(s) in Scripture, Enoch for example, who apparently did not experience death. If you did, then you will recognize that there is another, infallible, source of knowledge available to us; a source which can help us move beyond a mere rational or experiential analysis of truth.
Now if we think about these principles in light of some of the standard proofs offered for the existence of God, we can begin to see the apologetic problem. Suppose we think of a causal argument:
For the sake of brevity, we can say that the first two premises are obviously true. But what about Premise 3? Can there be an infinite regress of causes? How could we know such a thing? What access do we have to infinity so that we can pronounce on its properties? Are there rational or experiential laws that give us the needed characteristics of infinity? Or maybe all that Premise 3 wants to affirm is that causes cannot go on endlessly; there had to be a starting point, something that got the whole causal chain going in the first place.
This sounds patently true to us, and it should if we're Christians. The question to be asked, however, is whether or not someone who is not a Christian is driven by rational or experiential laws to see its truth. Is there, to employ our two categories above, a rational reason that requires one to affirm Premise 3? What would that reason be? It couldn't be that reason requires that there be a first cause because that is the question at issue, and a causal requirement surely assumes our experience of causes. If there is no rational reason, is there an experiential one? Do we have experience of a first cause? No, as a matter of fact, all of our experience is just that causes seem to go on and on and on. As many have pointed out, all that is required for a series of causes is the presence of a previous cause, not of a first cause. Examples like this could be multiplied to include notions of necessity and contingency, design, and so forth.
So, what's a Chrisian apologist to do? It might help to recognize the structure of persuasion in all of our attempts to defend Christianity. Tenet 9 affirms both a subjective and an objective aspect to this persuasion. Subjectively, as we have seen, the person to whom we speak already knows God, the true God. He knows that he is God's creature, that he has sinned against his character, that his sin deserves death, that he should repent and give honor and thanks to God. Because he knows, by God's activity in and through creation, all of these things, any time we communicate God's truth to him, that truth gets through to him. In other words, if we think of persuasion as the attempt to "connect" what we are saying with what the other person knows, then the communication of God's truth is, by definition, persuasive; God's truth always accomplishes the purposes for which he sends it.
We need to be wise, of course, in how and what we communicate. Even as we affirm that God's truth always hits its mark in those who hear it, it is usually less than persuasive simply and abruptly to approach someone and say, "You're going to hell. Are you interested in hearing more?" Wisdom requires, at least, that, as far as is possible, we take into account the one(s) to whom we speak so that we might draw them into the discussion. This, as we have seen, was Paul's chosen approach to the Athenians, as he determined to quote their own poets in order to tell them who God is.
The objective persuasion point has to do with our previous Tenet. Since God, in his mercy to all, restrains the depth of depravity in those who are outside of Christ such that they are able, often with great effect, to affirm the right things and to live lives that are anything but chaotic, we can use those "right things" and "good" lives to begin to question how they conform to a denial of God's existence. How can it be, we could ask, that basic laws of physics can be so uniform and calculable if the world is ever changing, lacking any real stability? In this way, we take those things that a person does believe and know, which he affirms to be true, and begin to question how his view of the world, or of his life, can account for such things.
Persuasion, therefore, recognizes the truth within all of us, as well as the "truth," superficial though it is, that God permits those who remain in Adam to affirm. There is, therefore, in our attempt to persuade, a revelational foundation that has to be recognized (not necessarily communicated) in the midst of our defense of the faith. Given such a revelational foundation, it may be that the causal proof above would prove convincing to someone. The fact of the matter is that there cannot be an ad infinitum series of causes because "in the beginning, God created." Since this knowledge is embedded in all people, Premise 3 above will meet its mark. But when we recognize that such premises have their ground and truth in God's revelation, and not in some neutral notion of reason or experience, then we will be intent on moving someone from mere notions of causality, to the purpose of God's "in the beginning" work -- i.e., that he might bring all glory to himself as he provides and accomplishes redemption for those who are his enemies.
In this way, no apologetic that claims to be Christian will be satisfied with mere theism. It will recognize that Christian theism requires Christ, or it is no true theism at all. God has provided the means of persuasion. All our proofs should recognize and incorporate those means, as we give reasons for the hope within.
Blind unbelief is sure to err,
And scan his work in vain;
God is His own interpreter,
And He will make it plain.
K. Scott Oliphint is Professor of Apologetics and Systematic Theology at Westminster Theological Seminary. His latest book is Covenantal Apologetics (Crossway, 2013)