Notes from Greg L. Bahnsen’s lecture series, Faith, Facts and False Worldviews.
What does everybody do when they do philosophy? They have to come to reliable presuppositions that undergird everything else in their study. They have to be able to unify the world into a worldview where every part of man’s experience has their appropriate place and everything is interpreted. Can theistic materialism do just that?
In order for you to refute a philosophy two things should be on your mind. You want to look at the worldview of your opponent and identify arbitrariness and inconsistency. Firstly, arbitrariness is not allowed in a philosophical outlook, because then it is not rational. It gives you no reason to believe that you have found the truth. Unbelievers need to justify their views. Ask them, “how do you know that?” Secondly, no one is allowed to be inconsistent. No one is allowed to contradict themselves when they put together their philosophy. Why are people not allowed to be inconsistent? If you are inconsistent then you can prove anything from inconsistent premises. If you can prove anything, then you are being arbitrary.
The proof that Christianity is true is that without it, you cannot prove anything at all. To put it another way, the Christian worldview is the transcendental precondition for intelligibility. So the atheistic materialist comes along and says that there is no God and no soul. There is just matter. My answer to that is, if that were to case you couldn’t know that were the case and you couldn’t prove anything at all.
The Problem of Induction/Causality/Uniformity of Nature
All science rest upon inductive inference. It takes something that we have experienced in the past and projects it into the future. Here is an example, you get up in the middle of the night and you walk around and stub your toe. The next night you get up in the middle of the night and walk around and you’re careful to not stub your toe again. If stubbing your toe last night hurt, stubbing your toe tonight will hurt to. The way things were in the past in terms of causal relationships will be things you encounter in the future too. Can you see why all science depends upon this? If there were no uniformity in the natural world, then all of your scientific experiments would be waste of time. You could learn everything you wanted about chemical reactions on Monday, but on Tuesday everything would be different. Induction is simply the view that the future will be like the past. Future relationships between events will resemble past relationships between events.
What will happen if I let go of this marker? Let’s say that you have never seen this experiment done before. The good philosopher will say that we have no way of knowing. I will now do the experiment. Watch closely! (it drops). We are now going to do a second experiment. You now know that one time, 20 seconds ago, this fell when I let go of it. What will happen when I let go of it this time? You don’t know. The reason you don’t know is because you have no basis for inductive inference. You have no basis for knowing the future will be like the past. You say, “well that was 20 seconds ago with the same conditions.” But you are assuming under the same conditions that one event will lead to the same event. You are assuming the uniformity of nature.
Now I’m a Christian, the reason I’m going to the science lab today is because I know that there is a sovereign personal God who governs this world. He controls it and makes it regular so that I can have dominion over it. My question for you Mr. Atheist is why you are going to the science lab today?
What are some ways one will try to recover from the problem of induction? The athiest says that they live in a random universe. He has no right to rely on inductive inference. He has no reason to expect the uniformity of nature! If he has no basis for the uniformity of nature, he has no basis for doing science. He will often retort, “Well very probably will the future be like the past. The reason why it probably will is because it has always done so in the past.” The problem is that he has smuggled into the argument the thing he’s supposed to prove. When I say that the future will probably be like the past, I’m basing that upon past information. In the past, the future has always resembled the past. I want to know how in the future, the future will be like the past.
The Problem of Deduction
It relies upon the laws of of logic. When we deduce conclusions, we take the laws of logic and truths that we know and we do operations on these truths draw conclusions.
P1. All men are mortal
P2. Gary DeMar is a man
C. Therefore, Gary DemMar is mortal
The relationship between these classes goes like this:
P1. All P is Q
P2. All D is P
C. Therefore, all D is Q
If we did not have laws of logic and we only relied upon isolated one time experiences, then we’d never be able to advance our knowledge. But because the laws of logic are valid, we are able to learn a whole lot about things. If I know that all men are mortal and that Gary DeMar is a man, I don’t have to wait until Gary dies to know that he is mortal. It follows from the premises that he is mortal.If he doesn’t die, then the proposition that all men are mortal is not true. If I know that all men are mortal, then we know that that person will die. Another deductive inferences goes like this:
P1. If P then Q
C. Therefore, Q
Every argument that is in this form is a valid argument. If the premises are true, then it follows that Q must be true.
P1. If Dr. Bahnsen was a wealthy man, he would not be living in the dormatory.
P2. Dr. Bahnsen is a wealthy man.
C. Therefore, Dr. Bahnsen is not living in the dormatory.
At least two things must be isolated for analysis: the concept of mortal, humanity, and laws of inference. To do deduction, you need to be able to identify classes and laws of logic. You are talking to a materialistic atheist who says that all of reality is material in nature. If all of reality is physical in nature then what are classses? Are the class of “mortal” and “humanity” physical things? Let’s say the unbeliever wants to do mathematical reasoning. He says that we know certain deduction relationships such as 2+3=5. I have a question for you, is this “2” and “3” and “5” on the blackboard? If this is “2” (Bahnsen erases the number 2 from the blackboard) we have just destroyed the #2. What I just erased was just an instantiation of the concept “2”. The concepts themselves are not physical. Are the laws of logic physical things? If the atheist believes that everything is material, there cannot be any laws of logic. If there cannot be laws of logic, then there cannot be deduction.
The Problem of Mind
We are dealing with a materialistic atheist, so does he think that I have a mind or that he has one? Make sure that you know the difference between a mind and a brain. It makes sense to say that my brain is 5’10” off the floor, but it makes no sense to say that my mind is 5′ 10” off the floor. Is what you think in your mind boiled down to what takes place in your brain? Is it even possible for a scientist to open my head and do a scientific procedure on my brain and predict what I will do? It would be impossible. Looking at electrons, and molecules and synapses has nothing to do with what is the conceptual content being transmitted over those synaptic archs and so forth. The atheist has got to say that mind reduces to brain. Here is the kill, if this is true, then atheists don’t have control over what they think. If what atheists believe is true, then they have no reason to believe what they believe is true. All their talk about atheism just reduces to electro-chemical responses in their brain.
Problem of Moral Absolutes
In my debate with Gordon Stein, I suggested that what if I were to take out my gun and ask him, “give me an argument for why I shouldn’t shoot you?” He has two ways to go, he will either say that there are no moral absolutes or say that it is wrong to win a debate by shooting your opponent. If there are no moral absolutes, then I could just shoot Dr. Stein. If he says that I could not shoot him, then he’d have to justify that there is moral in this universe than just matter in motion. Every atheist you talk to is on the horns of this very dilemma.