On dualism

I had a brief exchange with a good friend on Facebook recently. My friend is basically a freethinker like me and, I believe, an agnostic. But one area where we disagree centers on the issue of dualism, or the notion that the mind is somehow separate from the physical brain. I don’t want to do my friend the disservice of paraphrasing his words and mischaracterizing his position, so I’m going to quote our exchange verbatim.


It is truly amazing and confounding, trying to figure out the “hard problem” of consciousness. But it’s a physical system. No miracles required.

My friend:

Let me ask you. The fact that there is anything (physical or non-physical) seems to conjure up perplexing question as to how it came into existence. I can think of only two options. One, it always existed. Two, it came from nothing. Neither one of these makes logical sense. Yet — I’m sure something exists — either physical or my mind.

So didn’t something defy all logic to exist? Isn’t it reasonable to say this is miraculous? Isn’t it also very humbling ~ to degree being too sure of one’s opinions is almost silly.

What form of physical matter could either create itself from nothing OR just always exist? If you can’t answer then how do you know it’s all a “physical system?”

Obviously my friend is a deep thinker and for that I am grateful. I relish the opportunity to discuss these things, so I promised him I would answer when I had enough time to collect my thoughts. I decided to eschew Facebook and form my response in my long-neglected blog. (Another friend made me think of my blog today.) So here goes.

The first thing that strikes me in my friend’s reply (lets call him Andy) is the appeal in the first paragraph to whether “something from nothing” makes sense. As Neil deGrasse Tyson is fond of saying, “The universe is under no obligation to make sense to you.” This may sound flip, but it actually reveals a much deeper truth.

My ancestors, the Greeks of classical times, tried to explain the world pretty much solely by means of reasoning, with little in the way of observation and empiricism. They formed brilliant arguments based on reason alone, and made great strides in knowledge, particularly in the field that today is known as philosophy. But their advances in technology never matched those of their philosophy. And the explanations they came up with fell far short of reality.

Common sense, reasoning, and logic are powerful tools for navigating life on a day-to-day basis. These tools evolved to help us survive in a world where one had to be able to outwit predators, weather, fickle food sources, and other problems faced by a relatively weak, slow, defenseless, and hairless ape. These faculties excel at all that; they are the main reason we are here today, rather than eking out a living among the trees of Africa.

But these capabilities fall woefully short when it comes to understanding the underlying nature of reality, the things which are are normally beyond our senses. Einstein’s general theory of relativity is among the most battle-tested pieces of explanatory knowledge in the history of civilization. But does it comply with common sense, with logic, with human experience? Hardly!

No amount of reasoning or intuition can arrive at some of the most profound mysteries of the universe. So let’s dispense with the notion that “not making sense” precludes an explanation from comporting with facts.

It’s true that — depending on your definition of “nothingness” — we have never seen something arise from nothing. (Lawrence Krauss begs to differ, but I am aware of the debate around his contention that the universe did arise from nothing. What is “nothing”? Vacuum energy? Virtual particles? Again, common sense is no help here.)

My contention is that the fact that we have never seen something arise from nothing is scarcely proof that it is impossible or that it has never occurred. We’ve never seen dark energy or dark matter either, but that doesn’t prove they don’t exist. (They may not exist; the jury is still out — but the point remains.)

Now we get to the real heart of the debate — physicality versus non-physicality or the natural versus the supernatural. Science, as we know it, is based on the principal assumption that reality can be discovered and defined in terms of only that which can be observed, measured, and tested. If it can’t be observed, measured, and tested, it is by definition beyond the grasp of science. We call such things by words including non-physical, metaphysical, miraculous, or supernatural. I maintain that that science as we know it (the natural) is all we need to explain everything in human experience. I believe this is powerfully evidenced by two self-evident propositions:

  • the natural approach has been the most successful method for both explaining and applying human knowledge ever devised
  • there has never been any phenomenon proven to exist that demands an explanation outside the realm of the natural (i.e., the supernatural or miraculous)

Could there be undiscovered phenomena “out there” in the vast universe that we would consider to be supernatural? Of course it’s possible. But if the laws of nature are pretty much the same everywhere, then it’s highly unlikely. And if they are not, then any phenomena that occur on those nether regions would not apply in ours. Therefore, I dismiss any and all claims to such things as psychic phenomena and the notion of a “ghost in the machine” or spirit entity that comprises the human mind.

Need further evidence? I maintain that everything we know about the situation is supported by the proposition that the brain is all there is to what we call mind. In neurology, it is well understood that physical and chemical changes to the brain directly correlate with behavior. Damage to a particular part of the brain leads to impairment or change to a behavior associated with that part. How could there be a “personality” or “soul” apart from the brain if the brain is solely responsible for behavior? Similarly, we know that consciousness is a precarious state, easily lost by a blow to the brain, an introduction of certain chemicals, or death.

If the hypothesis of dualism holds, then there should be evidence at least as strong for the contrary view. Yet all we have are weak anecdotal tales of “out-of-body” experiences, near death encounters, disembodied spirits or ghosts, and so on. Unlike the evidence for the physicality hypothesis, all this is quite flimsy.

Finally, I want to be clear that I am not claiming to be certain that I am right. In science, there is no such thing as absolute certainty — all knowledge is considered tentative. If a better hypothesis comes along and is supported better by evidence, I will happily change my view. Until then, I live my life as though this physical world is all there is. And what a wonderful, awe-inspiring world it is!

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