Understanding what we are determines how we treat one another. In this series I’ve argued we are essentially a soul-body combination (Substance Dualism). But some say we are essentially material—only a physical thing. Over the past few weeks I’ve discussed five reasons given for this view, and showed why these arguments fail. We now come to the final argument for Physicalism.
Driven largely by the Enlightenment Scientism I discussed last week, some hold out for a “half-way house” between Physicalism and Substance Dualism. They argue that we are ultimately physical (bodies with brains), but our brains also produce immaterial properties. This, they believe, saves Physicalism from the devastating critiques I’ve discussed earlier.
This view is known as “Property Dualism” (variations are known as “Non-Reductive Physicalism,” “Epiphenominalism” and “Emergent Dualism”). As we might expect, this is a popular view among non-believers. Surprisingly, it is also embraced by some believers, including some teaching at Christian colleges and seminaries (such as Nancey Murphy, a leading proponent of Non-Reductive Physicalism who teaches at Fuller Seminary). But this last attempt cannot save Physicalism either.
Reason #6 for Physicalism: Property Dualism is the Answer to Physicalism’s Problems!
Property Dualism say we are fundamentally physical beings. However, our physical nature causes both physical and non-physical properties. Just as fire produces something with very different properties (smoke), our brains can do the same. It can cause things with very different (non-physical) properties—thoughts, beliefs and desires. So our physical being has both physical and non-physical properties. Hence Property Dualism.
Property Dualism is attractive to those committed to Physicalism, but who are not willing to bite the bullet and say what “hard-core” Physicalists say—that “No one has ever had a thought in her life” (since thoughts are immaterial things, which can’t exist). Most Physicalists know that we have thoughts all the time (even to make this claim presupposes one has the thought that no one has ever had a thought!). But they don’t want to accept Substance Dualism either. So Property Dualism seems to give them a way out of this dilemma.
Property Dualism is attractive to some Christians as well. They don’t want to deny the soul exists, that we have a mental life, that we can live after the death of our bodies, and so on. But they have also embraced the Enlightenment epistemology of Scientism. So to be respectable they must accept that only scientific explanations are “real” explanations. Therefore they can’t accept Substance Dualism, for this goes against this current scientific orthodoxy. Property Dualism also seems like a good solution to them.
For Property Dualism to solve the problems of Physicalism it must offer better explanations of the data that the Substance Dualist’s explanations. So how does it do? Not very well.
1. Does Scripture Support Property Dualism? No!
The Substance Dualist maintains that Scripture assumes Substance Dualism. Christian Property Dualists go to great lengths in an attempt to make their view consistent with Scripture. This is an utter failure, as Scripture is very clear that we are a unity of a soul and body. Perhaps the clearest statement of this is II Corinthians 5:6-8:
Therefore, being always of good courage, and knowing that while we are at home in the body we are absent from the Lord— for we walk by faith, not by sight—we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord.
Paul identifies two realities: one in which we are in our bodies, and a second in which we are no longer in our bodies, but rather are in the direct presence of the Lord. There is simply no other way to understand this besides Substance Dualism—we are now a soul in a body, but at death our soul leaves our body and enters the direct presence of the Lord.
Furthermore, Scripture is clear that our physical bodies will one day be resurrected and re-united with our souls. For instance, I Corinthians 15:42-44 tells us:
It is the same way with the resurrection of the dead. Our earthly bodies are planted in the ground when we die, but they will be raised to live forever. Our bodies are buried in brokenness, but they will be raised in glory. They are buried in weakness, but they will be raised in strength. They are buried as natural human bodies, but they will be raised as spiritual bodies. For just as there are natural bodies, there are also spiritual bodies.
Notice that our earthy bodies are put in the ground when we die. But one day our bodies will be “raised to life” in a new, glorified state, and re-united with our souls. We will then live on eternally as a duality of soul and body again.
In fact, Jesus’ resurrection is said to be an indication of this final resurrection. He is the first to receive back his resurrected body, “showing the way” to help us understand that our bodies will also one day be resurrected:
But there is an order to this resurrection: Christ was raised as the first of the harvest; then all who belong to Christ will be raised when he comes back. (I Corinthians 15:23).
Without a prior commitment to Physicalism, no one can honestly say the Scriptures do not teach Substance Dualism. For more on this I can do no better than to point again to John Cooper’s masterful survey of the clear biblical teaching on this—Body, Soul & Life Everlasting: Biblical Anthropology and the Monism-Dualism Debate.
2. Can Property Dualism Explain Our Awareness of Our Soul? No!
Can Property Dualism give an equally plausible explanation of how we seem to be aware of ourselves as a self, or as a unified soul? Not to date. In fact, the Property Dualists can’t even offer an alternative explanation for our awareness of our soul, because doing so will beg the question. To do so the Property Dualist would have to assume that “he” first exists in order to give an alternative explanation of this awareness “he” is having. But there can be no “I,” “me,” “my,” “his,” “her,” or other indexical to identify a “self” for the Property Dualist. Only by assuming Substance Dualism can such words be used. So Property Dualism cannot, even in theory, offer an alternative explanation for the fact of our self-awareness of our soul.
3. Can Property Dualism Explain Our Mental Life? No!
Property Dualism argues that mental properties exist, but are caused by and “ride on” the more basic physical reality (the brain). Staying with the analogy often used by Property Dualists, this is akin to smoke being different from fire, but still caused by fire as the more basic physical reality.
Yet this doesn’t explain the most important part of our mental life. What must be explained is how mental properties, such as thoughts, can cause physical properties and events, such as neural firings and hand movements. But notice that the cause and effect goes only one way in the Property Dualism analogy. Fire causes smoke, but smoke does not cause fire.
This is a significant problem for Property Dualists. They are aware of this, and work hard to provide a plausible, explanation of how these mental properties can produce physical effects. To date they have not been successful in providing a plausible explanation, much less a better explanation for what is easily explained by Substance Dualism.
4. Can Property Dualism Explain How We are a Unity at a Time? No!
For the Property Dualist mental events arise from the brain (again, as smoke arises from fire). But these are each discrete mental events. They in no way can be unified into a whole for the Property Dualist. For this you need a substance for the properties to adhere together “in.” But this is precisely what Property Dualism rejects. Therefore the Property Dualist cannot explain how we are a unity at a time.
5. Can Property Dualism Explain How We are a Unity Through Time? No!
Similar problems arise when the Property Dualist tries to explain how we are a unity through time. As I argued in more detail earlier, based on the Law of Identity there can be no sameness throughout the constant changes of the body without an enduring substance to “stand under” these changes.
6. Can Property Dualism Explain The Law-Like Change We Observe? No!
The Property Dualist fares no better in attempting to provide a better explanation of the law-like change and “oughtness” we observe in humans persons. Nature only explains what is, not what ought to be. Only an immaterial nature provides an adequate explanation of this oughtness and law-like change.
7. Can Property Dualism Avoid Being Self-Defeating? No!
Property Dualism is self-defeating for the same reasons (Pure) Physicalism is. To argue for her view the Property Dualist must assume propositions, intentionality, logical relations, and choices exist, and are all “had” and “made” by an immaterial self (see here for more). But again, to assume this is self-defeating.
8. Does Occham’s Razor Help Property Dualism? No!
Occham’s Razor is not a friend of Property Dualism either. In fact, by suggesting such properties come from matter but are not material, the Property Dualist is offering a theory that is much more complex than Substance Dualism. This is even more so the case if the Property Dualist attempts to explain how these immaterial properties of matter can in turn somehow have causal powers over that matter. So Occham’s Razor not only fails to support Property Dualism, it is actually a further reason to reject it.
9. Can Property Dualism Avoid the Problems of Scientism? No!
Lastly, Property Dualism commits the same logical fallacies as (Pure) Physicalism in assuming Science has proven there is no soul or immaterial substance. It is clear that much of the motivation of the Property Dualist is to save Enlightenment Scientism. But positing these non-material properties coming out of the physical properties (and not being reducible to the physical properties) does not save Property Dualism against the criticisms of Scientism made last week.
In sum, there seems to be no good reason to stop at this “half-way house” of Property Dualism. It is driven by the fact that arguments against Physicalism are persuasive, and so there must be some non-material aspect to human persons. This is to begin journeying on the path to Substance Dualism. But Property Dualism does not solve these problems. Only by traveling all the way to Substance Dualism can these problems be avoided.
There remains one other answer to the foundational question “What are we?” I’ll discuss that next week. Until then, grace and peace.
For further reading I suggest Philosophical Foundations For A Christian Worldview by J.P. Moreland and William Lane Craig; Chapter 11: “The Soul–Body Problem and Chapter 14: “Personal Identity and Life After Death.”