Dominoes, Determinism, and Naturalism

Author Greg Koukl Published on 04/22/2013

Those who choose to believe in determinism or physicalism don’t choose to believe at all—they believe because of prior physical conditions.

I want to talk about a concept that I’ve been rolling around in my mind. In fact, I’ve talked to you about it before, but it has come to the front of my mind because I’ve started to take classes again in my master’s program over at Talbot under J.P. Moreland. It’s a class on metaphysics dealing with naturalism.

Naturalism is the idea that the only things that really exist or matter in the universe are physical things operating according to natural laws. There is no God outside of the system. There are no miracles. There are no hidden forces that drive the universe. There are no souls or spirits. There are no prophecies. There is no inspired Scripture. It’s just physical stuff operating according to physical laws.

Of course, you can easily see that is this in direct contradiction to many things in the Christian world view and therefore is hostile to Christianity. One of the underlying claims of naturalism is that human beings can be reduced to mere physical things, and this is especially dangerous to Christianity because it means we have souls.

First, you can imagine the consequence for moral behavior. Second, if we don’t have souls, it seems hard to argue that Christianity is even possibly true. Let’s face it, Christianity talks about God and our relationship with Him, and our spending the rest of eternity with Him. We die, to be absent from the body is to be present with the Lord, according to the Apostle Paul. If we die, our bodies are where? In the ground. And our souls are with God. But if we are our bodies, then our souls aren’t with God because our souls don’t exist and we are where? In the ground because we are our bodies.

This is the primary dogma right now in philosophy of mind and in neurological sciences. Everything is bent towards trying to reduce human beings to the physical makeup. A brain, central nervous system, feelings, emotions—all of these things are simply the result of evolution. Behavior is dictated by our genes. Everything is built into the body.

As Time magazine said in 1995, “There is no you inside of your body that is directing it, governing it, and making it happen.” They don’t know what consciousness is, but they know one thing for sure. There is no soul.

Having laid that foundation, I want to offer you an understanding of why such a thing is seriously problematic.

First, I think is a very powerful and compelling reason. The point of view is that if such things are true, if there are no souls, that there are only physical systems, brain, central nervous system, synapses firing, and that kind of thing, then we could never know it. That’s my point of view. If we are entirely physical, if there is no soul, then we could never know it.

Let me give you my argument why that’s the case. If you are following me at all, you are realizing that if someone wants to assert physicalism and it can be shown that physicalism can never be known if it is actually true, then it’s going to undermine the rationality of holding that point of view.

Let me give you the reasons why physicalism could never be known. I’ve got to start back a couple of steps.

Science seems to work pretty well. It seems to work pretty well for a reason. When you study something scientifically, it keeps happening on a regular basis regardless of where you are. If the conditions are the same, the result is always going to be the same. That is called experimental repeatability. That’s why they do repeat experiments to see if the result is always consistent. And if it is always consistent, then we seem comfortable in saying we have stumbled upon some kind of scientific principle that can be relied on or some kind of scientific law. That is, it operates according to a uniform pattern.

But why is it that things in the physical universe operate according to a fundamental and predictable pattern? It’s very simple. Physical things don’t make decisions. Any physical action turns out to be a reaction to something happening before it.

You ask, why did the earth shake when we have an earthquake. Because of the shifting of the earth’s surface. Why did we have this local shifting? Because of plate tectonics. You could in principle keep going back and back asking why? There will always be some other physical cause before it. So for any particular event, there is a series of physical causes that resulted in that event. And not just resulted in it, but necessitated it.

It’s like a series of dominoes falling. When any particular thing happens in the physical universe we ask ourselves what was the domino before it that caused it? And what was the domino before that? You can chart that. This just points out that all physical systems are deterministic. Every single action is determined, brought by a prior physical action. Science is the discipline that is meant to discover those prior physical conditions so that if we recreate the prior physical conditions, if we set up the dominoes in the exact same way, they are going to fall in exactly the same way every single time.

So the effectiveness is predicated on the idea that physical systems fall like dominoes. You probably never thought of it that way before, but I’m sure you are very familiar with the concept. What caused that other thing?, is the question we often ask. If you have that in your mind, that all physical systems are just a matter of series of dominoes falling and humans are just physical systems, then you will understand why if that is the way reality actually is, we could never know it to be the case.

If we can’t know it, we certainly can’t assert it as so. It might secretly be the case, but we couldn’t know that from any rational analysis. Why would I say a thing like that? Here are the reasons.

Science works because physical systems are strictly determined. Therefore they are very predictable and we can set a certain set of specific initial conditions and always know the outcome of those conditions. Science depends on a deterministic physical universe.

Now, of course, that turns out to be the problem, doesn’t it? Some of you are thinking ahead a little bit. I mentioned that it’s like a row of dominoes falling and in many cases, the cause and effect relationship for any effect that we view may be the result of a very sophisticated flow of dominoes, but they’re just dominoes nonetheless when you get down to the basics.

Picture in your mind two lines of dominoes that are falling. And at the end of the line of dominoes is not another domino, but there is actually a human being, a person standing there right next to a cliff. What happens when the last domino falls and lands on our poor unsuspecting person at the end of the line of dominoes? Well, low and behold, just as every domino has fallen up until then, the last domino strikes the human being and he falls too, right over the cliff. Now, here is my question. Given that scenario, did that person jump off the cliff? The answer is no, of course not. He was pushed. What was he pushed by? A falling domino, a big one, adequate to shove him over the cliff.

Now, what if the person who fell over the cliff actually thought he jumped on his own. Would he have done just as he thought? The answer is, of course no. The guy thought he jumped over the precipice but it was really a domino that pushed him.

The question comes to mind, why would somebody think they jumped when in fact they were pushed? How could they be deceived in such a way? Obviously if they see the dominoes falling and strike their body, they are thrust out over the cliff, and they know they didn’t do it.

Well, sometimes the dominoes are not visible. Sometimes they are invisible. Sometimes they are not external. Sometimes the dominoes are internal. Just as external physical forces can cause us to do things. Certainly internal physical forces, like genetics, can cause us to do something, as well.

On the physicalist view of the universe, everything is dominoes, whether you see them or not. Whether they are outside or inside, everything is dominoes. Sometimes we think we are jumping, but the fact is we are not. Instead, he fell because of prior physical conditions that were sufficient to cause the effect of us jumping one way or another. We are always pushed if there are only physical causes in the universe.

Now, let’s just make a small change in the illustration and you will see the problem with physicalism. What if he is not choosing to jump, which would be an illusion according to physicalism because he was pushed by the dominoes, but instead he chose to believe proposition.

Now, whether he is choosing to jump or choosing to believe, on the basis of physicalism neither of them are real choices. Whether it is the choice to jump or the choice to believe, the choice isn’t a real choice, it is just an invisible domino that caused him to act in that way, whether it was a physical act or a mental act. Once again, it’s all dominoes.

If that is the case, then what of the choice to believe that physicalism is true? You see, some people want us to choose to believe that physicalism is true because they’ve offered the evidence that we can consider, and the smart guy will put his money on physicalism as the point of view that is best supported by the evidence. However, if physicalism is true, then none of the choices we make are real choices, are they? Because then there would be a will acting freely. But there is no room for wills acting freely in physicalism. Everything is governed by prior events. Dominoes falling.

If it’s all physicalism, it is all determinism. You and I never choose to do something or choose to believe anything. It is always chosen for us in a sense, we were pushed by the prior conditions that cause our physical state of mind or our physical actions. There is no free will if physicalism is true. There is no free will to jump or not to jump. There is no free will to believe or not to believe. Our thoughts and our beliefs are determined by prior physical conditions.

Therefore, knowledge would not be possible, ladies and gentlemen. The reason we employ reason is because we believe people can make free will choices based on good ideas and good evidence. We say you ought to choose to believe this because there is good evidence that ought to inform that decision. It presumes we can choose. But if physicalism is true, we don’t choose anything. We certainly don’t choose to believe anything, therefore reasons are irrelevant.

In the final analysis, those who choose to believe in determinism or physicalism don’t choose to believe at all, they believe because of prior physical conditions. And those of us who choose to believe in some religious alternative, free will, and rationality didn’t choose that either. Our beliefs were predetermined by prior physical conditions, falling dominoes.

In neither case do we know anything. We just believe what we have been determined to believe by the falling dominoes.

If physicalism is true, then physicalism leads to determinism, and determinism makes knowledge impossible. Therefore, if physicalism is true, you would never be able to know it as all the physicalists claim they do.