What Is Physicalism?

Post Author: Bill Pratt

In the previous post, we explained what substances, properties, and events are.  Now it is time to use those terms to explain what physicalists believe about human beings.  Philosopher J. P. Moreland explains below:

According to physicalism, a human being is merely a physical entity.  The only things that exist are physical substances, properties, and events.  When it comes to humans, the physical substance is the material body, especially the parts called the brain and central nervous system.  The physical substance called the brain has physical properties, such as a certain weight, volume, size, electrical activity, chemical composition, and so forth.

As far as human beings go, physicalists hold that they are physical substances with physical properties.  But what about events?  Are they also physical?

There are also physical events that occur in the brain.  For example, the brain contains a number of elongated cells that carry various impulses.  These cells are called neurons.  Various neurons make contact with other neurons through connections or points of contact called synapses.  C-fibers are certain types of neurons that innervate the skin (supply the skin with nerves) and carry pain impulses.  So when someone has an occasion of pain or an occurrence of a thought, physicalists hold that these are merely physical events – events where certain C-fibers are firing or certain electrical and chemical events are happening in the brain and central nervous system.

Are you getting the idea?  Everything about human beings can be reduced to physical substances, properties, and events.  You might be wondering how physicalists explain our thoughts, emotions, and pains.  Are these also physical?  Yes, they are.  According to Moreland,

My conscious mental life of thoughts, emotions, and pain are nothing but physical events in my brain and nervous system.  The neurophysiologist can, in principle, describe these events solely in terms of C-fibers, neurons, and the chemical and physical properties of the brain.

For the physicalist, a human being is 100% composed of matter, and nothing else.  There is a further crucial point that needs to be made about matter:  “No material thing presupposes or has reference to consciousness for it to exist or be characterized.”

Moreland elaborates:

You will search in vain through a physics or chemistry textbook to find consciousness included in any description of matter.  A completely physical description of the world would not include any terms that make reference to or characterize the existence and nature of consciousness.

So now you have a description of what physicalists believe about the mind and body.  They affirm that the body exists, but deny that anything like an immaterial mind exists.  For them, everything about human beings, and the world in its entirety, must be explained by physical/material substances, properties, and events. 

In our next post , we will look at what dualists believe.

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  • Bill, you use the word “physicalists” as is this were a cult or some fringe branch of science. This is not the case. In fact, the idea that the human body is “merely” a physical being is what science tells us is true.

    You mention an “immaterial mind”. What reason do you have to believe that anything like this exists? Have you ever encountered a mind, without a brain? And you bring up emotions and feelings like they are some sort of magical, unexplained mysteries. Modern science has taught us much about how the brain works, so much that we can see which areas correspond to which feelings, and how stimulating physical parts causes patients to report experiencing specific emotions or feelings.

    I think it is dishonest for you to say “For them, everything about human beings, and the world in its entirety, must be explained by physical/material substances, properties, and events.” It is not that they “must” be, science does not work like this. It is descriptive, not prescriptive. We don’t come up with these precepts and go out and say “ok, we need to find a way to explain the brain using only a physical explanation”. That’s completely backwards. Scientists examine the world and then come up with explanations based upon the evidence, data, and results of experiments, etc. It is unfair for you to classify them the other way around.

  • Stay tuned for a defense of dualism in upcoming posts. This series will take a while as it is too dense to cover in just a couple posts. And by the way, you may want to read my recent post on why scientism is self-defeating. It sounds as if you hold a strong form of scientism. I could be wrong about you holding that view, obviously, but that’s how you’re coming across in your comment above.

  • Thanks for the reply Bill, I went back and found that post and read it over. I wouldn’t say that I hold a strong from of scientism, and I don’t really think anyone who holds a similar worldview as I would claim that scientism is a useful label for anything. It seems that religious believers have created the label in order to give the appearance of a similarity between religious believers and followers of “scientism”. Science isn’t an “ism”. As many people on your post correctly pointed out, you are trying to equate “scientific reasoning” and the “scientific method” with this created idea of “scientism”.

    Science is not self-defeating and is the BEST current path to truth that we have access to. Why is this the case? For one, it is because science is self-correcting. Unlike religions, which make absolute, timeless claims of certainty (even about things that are demonstrably incorrect, such as rabbits chewing their cud), science depends on testable hypothesis, which, when fail, are changed or corrected. Where is this mechanism in any major religion?

    Of course, it is not the ONLY path to truth. For example, I could guess what you ate for breakfast, and 1 out of, I don’t know, 1000 times for example, I could be correct. However, a better way to discover this fact would be to ask you, examine your kitchen, or even observe you eating. This would be the scientific method, and it is demonstrably more reliable and consistent than pure guessing (or any other current method). You are advocating for knowledge through faith, which I find to be one of the most ridiculous ideas ever. Faith is an excuse people give when they don’t have a justifiable reason for believing something.

    In one of your comments to another poster, you wrote:
    “There is a very strong connection between biblical faith and scientific reasoning”

    This could not be farther from the truth. You need to demonstrate that it is justifiable to believe in the bible. You can’t take the easy way out and say “just have faith”. Faith is not a reason, it is an excuse.

  • I don’t think you have any idea what faith in the Christian tradition is. I suggest you read this post and the follow-on post to get some idea.

  • Daniel

    “is what science tells us is true.” Because you said it’s true therefore it is. ? Science doesn’t tell us anything confused one, PEOPLE do. Science doesn’t THINK, PEOPLE THINK. You are truly deluded and don’t understand science. You’re not a philosopher, nor a theologian, nor a logician, otherwise you wouldn’t have made such a common, obvious and stupid mistake. You truly do worship an imaginary version of some Science God. It’s disgusting. You can learn how to be forgiven of your idolatry here: http://eternian.wordpress.com/life

  • Not sure why you think I said that science “thinks”. When I say it “tells us”, I mean that using the scientific method through experiments, forming and testing hypotheses, peer review, etc. we have learned… You are correct to point out that science doesn’t itself do anything. As I harped upon in my post, it is simply a method, a tool for determining facts, data, and information about the universe, from distant stars to microscopic cells. I do not worship science, it has no god like qualities, and asserting that I do really shows the depth of your ignorance and misunderstanding of these things.

    The condescending nature of your post and obvious self promotion really don’t do anything to help your case.

  • Cristero

    Strong scientism = ignorance of philosophy of science

    “science is self-correcting” – read Kuhn

  • donsalmon

    I’m afraid I don’t understand how the word “physicalism” has any coherent meaning. You say certain “properties” are “physical” but there is still no definition of physical. I’ve spoken to scientists, philosophers and others who have studied this, and the consensus is that there is no affirmative meaning of the word. The only meaning everyone agrees on is “it’s not mental”.

    So I don’t understand how we could ever know anything physical even exists. If “physical” means something that exists entirely apart from any kind of awareness whatsoever (not just human awareness but any awareness) then in principle it is unknowable. It can only be asserted as a matter of pure faith. Since no scientific experiment requires this assertion of faith, why believe in it? It requires us to believe in an endless succession of miracles more fantastic than anything in any religious text:

    1. That something just emerged out of nothing.
    2. That something, the cosmologists say, was pure chaos. We are next to believe that, in an utterly mindless, dead, unconscious universe (consisting of what? Remember nobody can define positively what physical means) order suddenly emerged (what used to be called “laws of nature” and now are meekly referred to as “regularities”).
    3. Then, as if that were not miraculous enough, when one would expect this chance-based order to simply fall back immediately into chaos, we are asked to believe in a pure mindless dead void, this order CONTINUED for billions of years.
    4. Next, we are asked to believe that life simply “emerged” miraculously out of the deadness of this physical something we can’t define. If you think life is easy, ask a biologist – recently, a group of high level biologists spent a day at a conference trying to define “life” – nobody could even agree on a basis for the discussion much less a definition.
    5. next we are asked to believe that emotions, thoughts, mind, perception, awareness, self awareness, simply “arose’ miraculously.

    I’d rather believe in Noah and Jonah than this incoherent babbling nonsense!

    “Shaving Science With Ockham’s Razor