By Evan Minton
C.S Lewis once wrote “You don’t have a soul, you are a soul. You have a body“. Most Christians believe that we are not merely physical bodies, but that we are immaterial entities that live inside our bodies. We are embodied spirits. This view is known as Substance Dualism. The Bible very clearly teaches substance dualism (see, for example, 1 Samuel 28, 2 Corinthians 5:6-8, Philippians 1:20-22, 2 Corinthians 12:2-4), so if you believe The Bible is divinely inspired and inerrant, then you ought to be a substance dualist. However, how would you demonstrate the reality of the soul to someone who doesn’t believe The Bible is divinely inspired? Quoting passages to prove that souls exist would do little good when talking to an atheist or an agnostic.
Fortunately, there are philosophical arguments we can draw on for the existence of the soul. One such argument is The FreeThinking Argument which I briefly surveyed in my blog post “5 Arguments For The Existence Of Free Will”. However, another argument reasons to the soul’s existence from the law of identity. This logical principle states that if you’re considering two objects, and every single property both objects have are in common, and there is literally nothing to distinguish the two, the most logical inference is that they are one in the same. That is to say, the two things really aren’t two things after all, but one thing. On the other hand, if the two things do have at least one property that distinguishes them, then the two things are totally separate entities.
In syllogistic form, the argument goes like this:
1: If the mind is identical to the brain, then whatever is true of the brain is true of the mind and vice versa.
2: There are things true of the mind that are not true of the brain.
3: Therefore, the mind and brain are not identical.
This is a logically valid argument. The conclusion follows from the premises by the rule of modus ponens. In order for the conclusion to be justifiably reached, we must affirm that both premises are true. What reasons can be given in defense of these premises?
Premise 1: If The Mind Is Identical To The Brain, Then Whatever Is True Of The Mind Is True Of The Brain and Vice Versa.
The premise rests on the law of identity. The physicalist (i.e the person who believes that people don’t have souls) must prove that when one is talking about the “brain” and when one is talking about the “mind”, they are talking about the same object. In order for them to really be one in the same, any property that the brain has, the mind must have. Any property the mind has, the brain must have. If physicalism is true, the brain must have properties A, B, C, D, E, F, G, and the mind must have properties A, B, C, D, E, F, G. Moreover, there must be no property or properties, H, I, and/or J which exists in one but not in the other. For if properties H or I can be found in one but not in the other, then this shows that they are different entities.
Imagine an alien were to visit from a faraway galaxy and he asked an Earthling who the current president of the united states is. The Earthling tells the alien that the current president is the former host of the TV show The Apprentice. Furthermore, this Earthling later learns from another person that The Apprentice only had one host prior to Arnold Schwarzenegger, Donald Trump. So, if the current president is the former host of The Apprentice, and the former host of The Apprentice is Donald Trump, then the alien would rightly conclude that the name of the current President is Donald Trump. He also learns that Trump is a Caucasian man and that it was a Caucasian man who previously hosted the television show.
Now suppose that this alien knows nothing of how the U.S government works and doesn’t know that a President can only serve a maximum of 8 years. He comes back 20 years later and asks someone who the current U.S President is and the Earthling tells this alien that the president is an Asian Woman whose previous trade was a movie actress, like Reagan. The alien takes into account the facts learned before, namely “The current president is the former host of The Apprentice“, “The current president is a man”, “the previous host of The Apprentice is a man”, and contrasts them with the new information that the current president is an Asian Woman. This is a distinguishing property. The alien concludes from this that Donald Trump must no longer be the current president and that the current president is an entirely different individual, an individual who did not host The Apprentice.
In the above illustration, the alien never actually saw pictures or videos of both of these U.S Presidents. He simply logically inferred based on the law of identity that Donald Trump was the president during his first visit, but that someone else became president before his second visit.
Donald Trump had properties (A) Prior host of The Apprentice, (B) Is U.S President, (C) is Caucasian, (D) is a man.
Years later, the alien found a person who (E) is U.S President, (F) an Asian woman, (G) was a Hollywood actress, (G) never hosted The Apprentice.
E, F, and G, are incompatible with A, C, and D. On this basis, the alien concludes they aren’t the same person. They do not have 100% of their properties in common.
Or another illustration: suppose your wife called you on the phone and said that she bought a bag of red fruit and set them on the counter. You come home to find red apples sitting on the table. You infer that the apples were the fruit your wife was referring to because (A) apple is a fruit, and (B) the apples are red. Your wife’s description and your observation connect to tell you that what your wife was talking about on the phone and what you’re now seeing with your own eyes are one in the same thing. Now, if you came home and found Granny Smith apples, you would think something is up. Although apples are a type of fruit, there’s a property that distinguishes them from the fruit your wife described on the phone, namely the color. You would infer that either your wife was lying, she’s color blind, or she bought two kinds of fruit and the fruit you’re looking at isn’t the kind she was talking about on the phone. But you would never say that the fruit you’re looking at and the fruit your wife talked about on the phone are the same type of fruit because they do not share 100% of the same properties in common. There is at least one property to distinguish them.
It can be stated simply: If X is identical to Y, then whatever is true of X is true of Y and vice versa. But if something is true of Y that is not true of X, then X is not identical to Y.
Premise 2: There Are Things True Of The Mind That Are Not True Of The Brain.
Now we come to the most crucial premise. Is the mind like the green apples and an Asian woman in the above illustrations? Do they have distinguishing properties that would lead us to conclude that are two distinct entities? I believe they do.
The mind has mental properties, such as the property of feeling sad, happy, angry. The mind thinks “about” things. For example, when I go for walks with my dog, I think “about” God, Jesus, philosophy, science, apologetics, or how lovely the trees in my yard looks. Sometimes I think “about” my childhood. The mind has the property of “aboutness” to it. The mind also has the property of first-person perspective. I know myself more intimately than anyone else in the world. I know first-hand what it’s like to feel my own happiness, my own sadness, my own anger, my own anxiety. I know what it’s like to be me. Moreover, the mind contains these things called beliefs, and beliefs can be either true or false.
3: Dr. Jacobus Arasmus, “Objections To The Existence Of The Soul”, November 20th 2017, http://freethinkingministries.com/objections-to-the-existence-of-the-soul/
This Blog was originally published by cerebralfaith.blogspot.mx here: http://cerebralfaith.blogspot.mx/2018/01/the-identity-argument-for-soul.html
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