on dualism

This post is adapted from a speech I gave at my Toastmasters club.

Today I am going to convert you. Not to a religion exactly but to a philosophical and spiritual concept called dualism. Dualism, stated simply, is the belief that we don’t have only bodies but also souls. We are not just one thing, the physical; we are a duality. We have a physical side and a spiritual side and both are real things. That is dualism.

The opposite of dualism can be called physicalism or materialism. That is the belief that the only thing that exists is matter and energy. First I’m going to illustrate a consequence of materialism that most people will find shocking. Then I’ll drop a little bit of logic in support of dualism. And finally, I will explain what we all need to do now that we are dualists.

What if materialism were true

Let's talk about the brain a little bit.

Did I really have a choice to pick a different image?

If I strike a pool cue ball just so, the balls would scatter in certain directions.  Now, imagine I perfectly set the balls back up and hit the cue ball the exact same way.  The balls would scatter the same as before, yes?  I mean provided nothing else changed such as the quality of the table, the atmosphere, the low-cut dress I am wearing, etc.  Put another way, if I knew exactly what the force is on the cue ball, I could predict the path and final destination of all the other pool balls.  As long as I had all the initial information I needed.  OK, next...

This one is a little tougher.  Instead of a few pool balls, how about millions of grains of sand in a sandstorm.  Imagine that we wanted to duplicate the same sandstorm twice.  Theoretically it could be done right?  Put the same sand grains in the same place and bring exactly the same wind and we'd get the same result.  Or again, if we knew just where all the sand particles are, what obstacles exist, and where the wind will blow, we could predict the end location of all the sand.

The difference between the sand and the pool table is you could conceive of someone actually predicting that outcome in the pool story.  It could be done in the real world by real people.  Measuring the sandstorm sounds quite a bit less doable.  I suppose given enough lasers and duct tape it could be done.  And one would need the help of dozens of ninjas.  And pirates.

So where am I going with this?

Here's my brain.  So pretty, right?

Without a soul, my contention is my brain is a lot like the sandstorm.  There's no practical way to measure in perfect detail what's going on in there.  But at least in theory it could be done.  And therefore, if you put me in a certain situation with certain stimuli hitting me, you could predict how I would react.  In other words, I do not have free will without a soul.  If we don’t have free will, there are tremendous implications in criminal behavior and ethics.  But that is another post.

another way of looking at the physicalist brain

I've been seeking an explanation of how free will and physicalism can be reconciled but I have yet to find it.  For the dualist, this problem is neatly solved.  The soul interacts with the brain in some way which provides that spark of free will.

I believe I have free will. Maybe I am deceiving myself and I don’t have free will at all. But if that’s the case, I was destined to do so and thus I have no reason to feel bad about it. Which leads me to...


Some wonderful arguments against physicalism were developed by Alvin Plantinga and others. Here is what Plantinga has to say:

If all of our thoughts are the effect of a physical cause, then we have no reason for assuming that they are also the consequent of a reasonable ground. Knowledge, is built by reasoning from the ground up. Therefore, if naturalism were true, there would be no way of knowing it.

Or as J. B. S. Haldane put it:

If my mental processes are determined wholly by the motions of atoms in my brain, I have no reason to suppose that my beliefs are true ... and hence I have no reason for supposing my brain to be composed of atoms.

Well, Q.E.D. as the philosophers say.

In Sum

As you go through life, you will get lots of advice. Save for retirement, eat right, don’t pick your nose in traffic, Team Jacob is superior in every way to Team Edward, etc.  That’s all great advice.   I have some more advice for all of you new dualists out there.

Don’t neglect the spiritual side of life. Think about what happens to your souls after you die. And then do what you think is right accordingly.

I am a liberal Evangelical so I have a journey that I am on. Dualism is compatible with most religions so if you ascribe to one you should feel right at home with this concept. And if you don’t, I hope you will think about dualism and free will...and let me know what you come up with.