Notes from Greg Bahnsen’s lecture, The Aim of Apologetics: Approach to Atheism.
There are two approach to defending the faith: presuppositionalism and natural theology.
The presuppositionalist says that we prove God by showing the impossibility of the contrary. This form of argumentation is indirect which says if you do not begin with God, then you destroy the intelligibility of human experience. The proof for God’s existence is that without Him, you wouldn’t be able to prove anything.
Natural Theology is the outlook that by correct use of reason and evidence, the unregenerate man can without assistance arrive at elementary religious truths. To put it another way, autonomously a man may come to a proper interpretation of God’s revelation in nature and history autonomously. The mind of the natural man has sufficient rational powers to discover God on his own. Natural theology seeks to offer proofs of God’s existence.
Critique of Natural Theology
Criticism 1: It is not clear what counts as a proof of God’s existence.
Here is a sound and valid proof of God’s existence:
P1. Nothing exists or God exists
P2. Something exists
C. Therefore, God exists
You cannot defeat this argument. Let’s look at it, is this a sound argument? You must have true premises and formal validity. Well it’s certainly a valid argument. Testing for validity always deals with the form of the argument.
Let’s test for validity (form):
P1. P or Q
P2. Not P
C. Therefore, Q
This by the way is a valid argument; it is called a disjunctive syllogism. If it is true that at least P or Q is true and one of them is shown to be false, consequently the other one must be true. Let’s begin with the minor premise: something exists. Does anyone have any doubt about this? Is the first premise true?
The first premise is true as long as one of the disjuncts is true. Well it is false if God does not exist and it is true if God does exist. One can reject P1. only if atheism has been proven. Since there are no good proofs for atheism we have no difficulty accepting that P1. is true, so if P1. is true, we have a valid argument with true premises. P2. just needs to cancel the other disjuct in P1. If P1. is true, consequently God must exist, because P2. shows that the first disjunct in P1. cannot be true.
What most people want is a convincing argument for God’s existence. What is a convincing argument? An argument where 1) the form of the argument is valid and 2) the premises are true and known to be true by all people. “Known to be true by all people” means each premise is proven independently of the conclusion.
P1. Nothing exists or God exists
-this is true if God exists, so if I know that God exists then I haven’t really given you a convincing proof of God’s existence. I was dependent upon the conclusion for accepting the first premise.
This is a ridiculously hard task to prove each premise independently of the conclusion. It is unlikely that there can be any conclusion proven convincingly to everyone.
Criticism 1: The Form of Proof Be Valid
When someone says that an argument must have a valid form, that person is assuming that there is an agreement on the rules of logic and the normative status of the rules of logic. There isn’t universal agreement of the laws of logic. Even where there is agreement, there is tremendous disagreement on their normative status. One of the elementary laws of logic is the Law of Excluded Middle, however, there are systems of logic which reject this. Don’t the laws of logic need to be proven as well? There are arbitrary assumptions in natural theology and they need to be exposed. There is no agreement on the foundations of logic. People have differing views of the nature of the laws of logic. Some think they are electro-chemical processes in the mind. Do they deal with propositions or assertions?
Criticism 2: Premises must be known to be true by all men
Knowledge and ingenuity vary from person to person. Not all men know the same things. An implicit prejudice will come into play regarding the rules of logic. The rules of logic must be taught in order to use them “our” way. Western universities would not allow Buddhists to give lectures on logic. Since not everyone knows the same things, we will have to define what is considered to be “educated” or “properly educated.” We will have no fixed termination point for a convincing argument; we only have a person relative termination point. Reaching a convincing point in an argument will be different from person to person.
Criticism 3: All premises must be proven.
Now if this is going to be a convincing are you laying this condition on me that I have to prove P1. and P2. by another argument? Let’s say I use argument A to prove P1. and I use argument B to prove P2., but you might not accept arguments A or B. So no I must use argument C to prove A and D to prove B. I can keep going on and on. Are you saying a convincing argument has an infinite series of proofs behind it?
a) No one has enough time to give an infinite number of arguments.
b) Argumentation would not be possible without a starting point.
Nobody can gain all of his knowledge by way of convincing argument! Some of the things we know, we know apart from convincing proof.
Criticism 4: Our premises must be known to be true by all men independently of the conclusion.
Perhaps the conclusion is one of our propositions, so then it would be wrong to demand a convincing proof. Or it may just be that my conclusion is itself necessary for knowing the other propositions in the first place.
Theological problems of Natural Theology
1. Is it the Living God or an idol which is proved by something that is more certain than God and known independently of him?
If something is known more certain than God and known independently of him, then we are not proving the Christian God.
2. It holds that partial elements of the truth about theism can be reached at the end of a reasoning process.
The Bible says it is the full truth that is objectively visible at the start of the reasoning process.
3. It thinks that the unbeliever can be fair and open-minded and use right reason and will affirm a portion of religious truth upon the strength of the evidence.
-Scripture views the unbeliever prejudiced about God, having a pre-judgment against the God of the Bible. He is closed-minded and suppressing the truth in unrighteousness.
4. Methodological Errors
a. natural theologians grant autonomy to the unbeliever
If we are defending the faith counter to what our faith teaches, then we are not defending it correctly. Our method should be adjusted to our method. The very method of the theistic proofs concedes the point we wish to refute–the autonomy of the sinner.
“In not challenging this basic presupposition with respect to himself as the final reference point in predication the natural man may accept the “theistic proofs” as fully valid. He may construct such proofs. He has constructed such proofs. But the god whose existence he proves to himself in this way is always a god who is something other than the self-contained ontological trinity of Scripture.”
b. natural theologians assume that people need the truth of God’s existence
“God has never left himself without a witness to men. He witnessed to them through every fact of the universe from the beginning of time. No rational creature can escape this witness. It is the witness of the triune God whose face is before men everywhere and all the time. Even the lost in the hereafter cannot escape the revelation of God. God made man a rational-moral creature. He will always be that. As such he is confronted with God. He is addressed by God. He exists in the relationship of covenant interaction. He is a covenant being. To not know God man would have to destroy himself. He cannot do this. There is no non-being into which man can slip in order to escape God’s face and voice. The mountains will not cover him; Hades will not hide him. Nothing can prevent his being confronted ‘with him with whom we have to do.’ Whenever he sees himself, he sees himself confronted with God.”
First of all the Ontological Argument. This argument focuses on causation as evidence for God’s existence. It argues that our experience of secondary causes must lead to a first cause of the natural order. To put it simply people will say:
P1. Every event has a cause
P2. What cause this even itself had a cause and this chain of causation goes back.
C. Thefore, there must have been a first cause in front of this chain. This first cause is what we call, “God.”
The Cosmological Argument starts with a premise based upon an observation of one thing causing another. It picks up our impetus from our desire for complete explanations of what we experience, and it moves to the conclusion that what we observe in the world where there are causal relationships must have added to the world God Himself as the first cause. From my perspective, the biggest mistake in the argument is the assumption that human experience and human reasoning are in themselves already intelligible, self-sufficient and stand by themselves. If you go to the unbeliever and you can experience something in the world which is intelligible by itself, you have already lost the argument. What I’m going to show you later on is that the unbeliever couldn’t experience anything intelligibly if God didn’t exist.
1. If someone says every event or object has a cause, then you must conclude that God Himself has a cause. God is an object so you must conclude that He too, had a cause. Christians should want to say every created event has a cause, but what unbeliever would want to accept that? Because if you say every created event has a cause then you have already assumed that there is a creation and a creator. This is the very thing you are supposed to be proving.
2. Even if respect to the created order, do we know from observation that there event has a cause? In a sense we do know that because the Bible says so, but that is not supposed to be smuggled in from this point. But as people we don’t know this because we haven’t experience every event in this world. If we would know it, we’d have to know it on the basis of divine revelation.
3. It doesn’t make sense to rule out an infinite regression because of the fact that universe could never have gotten started. An intelligent unbeliever wouldn’t even grant that the universe has ever started. It has always been here.
4. If you reason that there is a cause for each event, and from this conclude that there is a cause for all events, then you are engaging in an error of quanitifcation. Why does it not prove many of first causes?
5. If is fallacious to argue from the property of the parts to the property of the whole. This is an information fallacy to say that because the parts of something has this quality, therefore the whole has that quality as well. Every piece of my experience has something that caused it, but this doesn’t prove that the whole shares the same causal relationship. Let me give you an example. Let’s say my children got a set of 100 leggos for Christmas and I build a giant statue out of them. Each one of the leggos weighs less than one ounce, therefore the statue weighs less than an once. No this is silly. The quality of the parts is not necessary the quality of the whole. You cannot argue from the parts of the whole necessarily.
6. Even if all events in nature have a first cause, we have no basis to infer from our natural experience of causation that there is a non-natural cause for the world as whole. My argument is based on evidence taken from my experience of the natural world, but my conclusion has nothing to do with my experience of the natural world. My conclusion deals with a supernatural entity.