“If I can’t see it, it isn’t real.” This is another way people often express their belief in Physicalism. So far I’ve offered two reasons Physicalism can’t be true. In this final post on the topic I’ll offer a third….
In sum, if Physicalism is true, then we would have to reject all consciousness, including all rational thought. This is a very hard thing to admit, and therefore few Physicalists are willing to do so. But the honest Physicalist must be willing to say, with the few Physicalists who are willing to be fully consistent, that “no one has ever had a thought in his life” and “there cannot be a rational reason to believe in Physicalism.” Let me explain.
If Physicalism Is True, It is Not Rational To Believe Physicalism Is True
To understand this argument we must begin with what the Physicalist is actually claiming. The Physicalist assumes that if something exists, it is physical, or material. And matter is not “rational.” For example, pool balls are material objects. As we observe them rolling around a pool table we are not tempted to say they are in any way “rational.” That is just not one of the features these type of things have. They have properties such as being hard, moving quickly, or being to the left of or behind another ball. But they do not have the property of being rational. They are “arational” (without rationality). If someone claimed that somehow the pool balls are rational, you would wonder about that person! This would not change no matter how fast they move or what configuration they are in. They would still never have the property of being rational.
Since they are not rational, everything else which comes from them would also be arrational. For instance, if a photographer took pictures of the balls on the table, the pictures would similarly not have the property of rationality. If someone claimed that somehow the arational balls and their arrangements and movements produced rationality in the photograph that comes from them, you would also wonder about that person!
The fact is that material things, no matter what they are or what they are doing (how fast they may be moving or what their spatial relation to other material things may be), they are not rational, nor do they produce other rational things.
Now think about the brain. The brain is much like a (multi-surfaced) pool table. It has many small pool balls (molecules) moving around very quickly and colliding with one another. This is just what Physicalist’s say of human persons: "People are complex ‘machines’—personality (intellect, emotion and will) is an interrelation of chemical and physical properties we do not yet fully understand.”
In the words of Francis Crick in his The Astonishing Hypothesis: The Scientific Search for the Soul—
The Astonishing Hypothesis is that ‘You,’ your joys and your sorrows, your memories, and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. . . . This hypothesis is so alien to the ideas of most people alive today that it can truly be called astonishing.”
But, just like the activity of balls on the pool table, this activity of molecules in the brain must therefore also also arational—the molecules do not possess the property of rationality. And so anything arising from these movements and collisions would also be arational.
But the Physicalist assumes that out of this arational reality we get rational thoughts. There is no reason to assume this! One should conclude that anything which results from these collisions is also arrational, not rational. Believing rationality arises from these arational molecules colliding with one another is an unjustified leap in logic.
This is a huge problem for the Physicalist because Physicalism is one of the thoughts that, on the Physicalist’s view, arises from these arrational particles colliding with one another. Actually it is worse, because Physicalism is a large number of thoughts arranged together to construct this theory. Therefore, if Physicalism is true, no one should believe the theory is true, because it comes from arratioanl matter. Therefore there is no rational reason to believe Physicalism is true if in fact it is true.
The argument can be summarized this way:
- Everything that exists comes from matter (the Physicalist's starting assumption)
- Matter is arational (the definition of matter)
- There is no reason to assume anything produced by arational matter is rational (corollary of 2)
- Therefore, everything that exists comes from arational matter (from 1, 2 and 3)
- Thoughts and theories exist (assumed in arguing for Physicalism)
- Therefore thoughts and theories come from arational matter (from 4 and 5)
- Therefore, there is no reason to think any thought or theory produced by arational mater is rational (follows from 3 and 6)
- Physicalism is a theory produced by arational mater (from 1, 2, 3 and 4)
- Therefore there is no reason to think Physicalism is rational (from 7 and 8)
Many Honest Physicalists Agree
UC Berkeley emeritus professor John Searle observes, “[T]he leading problem in the biological sciences is the problem of explaining how neurobiological processes cause conscious experiences.” J.B.S. Haldane, who taught at both Oxford and Cambridge Universities, admits, “For 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. They may be sound chemically, but that does not make them sound logically.”
Christian philosopher Richard Purtill, professor emeritus at Western Washington University, summarizes the Physicalist’s conundrum well:
[Physicalism] gives us no reason at all to suppose that our reasoning is valid. Only conscious minds can have plans or purposes, so there is no plan or purpose that will ensure that our reasoning will attain truth. Forces that are without our mind might happen to give powers of valid reasoning, but they equally might happen to give us defective or invalid reasoning powers. And there is no reason to suppose that they would give us powers of valid reasoning rather than defective powers. Thus the views we have been considering [forms of Physicalism] are self-defeating in the sense that even if they were true we could never have any good reason to think that they were true.
In sum, if Physicalism is true, then we can have no good reason to believe it is true!
How To Point This Out To A Physicalist
One way to point this out is simply to listen for the inevitable “mental-ese” which creeps into conversations with Physicalists—phrases like “I think that…,” “it appears that…,” “it makes sense that…,” “it seems to me that…,” “the evidence suggests that…,” “I believe that…,” “my understanding is,” “For a number of reasons…,” and so on. These betray the belief in a mental life that is rational and should be trusted to find truth.
The problem, as discussed above, is that the Physicalists can’t defend this assumption. So, if asked, “Why do you only believe in what you can see?” or “Why do you think only Science gives us truth?” or “Why do you think I’m wrong?” she cannot say (consistently with her Physicalist worldview), “I think scientists have shown Physicalism is true” or “It appears the evidence is on the side of Science” or “It makes most sense that I should only believe what I see” or “It seems to me enlightened people don’t believe in things they can’t see” or “The evidence proves nothing exists that is not physical.”
As soon as such claims are made the Physicalist has embezzled immaterial things into her worldview—a mind, and the rational thought process and conclusions produced by that mind—that are capable of determining truth through a rational process. But she can’t claim a mind that can determine truth, given her Physicalism!
It Gets Worse: The Physicalist Can’t Have Emotions, Desires or Choices Either!
A similar point can be made concerning emotions, which by definition are non-physical, conscious states of a mind (not a brain). To be consistent the Physicalist must reject he has ever had an emotion. But few are willing to bite this bullet and admit this. Does he not love his wife and children? Does he not feel bad when disrespected? Does he not experience joy when his dreams (his what?!) come true?
Yet if he doesn’t bite the bullet he must try to explain these real emotions within Physicalism. This will prove very hard to do, if not impossible. And, of course, even the attempt to give a rational argument as to how emotions can exist within a Physicalist’s worldview assumes the possibility of rationality, the problem discussed above.
Likewise concerning choices, another non-physical, conscious state of a mind. To be consistent the Physicalist must reject she has ever made a decision. But she wants to argue(!) that she evaluated(!) the evidence and chose(!) Physicalism as the most rational(!) belief(!). It is this very fact of self-determination that makes her belief in Physicalism hers. The same is true of every other choice she has made—where to go to school, what to study, and what to believe about everything else. Yet to argue she has made any of these choices isn’t consistent with her Physicalism.
Lastly, the same applies to the Physicalist’s desires. He wants to say he desires to have true beliefs, he desires to be a good father, he desires to advance in his career, he desires to be tolerant, he desires to some day retire, and so on. But once again, to be consistent he can’t say such non-physical, conscious states of a mind actually exist. He must either deny he has any such desires, or give up his Physicalism.
In summary, to be consistent the Physicalist must reduce all mental states (reasons, thoughts, beliefs, desires, choices, emotions) to nothing more than physical (brain) states. Few are willing to do so. But by not doing so the Physicalist contradicts her view if she argues in favor of Physicalism, give reasons that it is more rational than a Super-physical (or Super-natural) worldview, or states she has other reasons, thoughts, beliefs, desires, choices, or emotions about anything!
It is safe to say that Physicalism is not, and cannot be true. On the contrary, a super-physical/super-natural worldview must be true—one that believes minds exist and can find truth through rational thought. Minds that can have emotions, beliefs, desires and make choices. This is ultimately to be found within the Christian worldview that grounds all reality in an infinite Mind that created us in His Image with these same capacities of rational thought.
Until next week, grace and peace.
For further reading I suggest Alvin Plantinga’s “An Evolutionary Argument Against Naturalism.” This is in a number of his books. An outline of a lecture he gave developing this argument is available online here.