The soul, the immaterial “breath of life”, was originally thought (I believe) to be where most of our thoughts, feelings, and personality originate. However, a lot of the functions of the brain, like cognitive thoughts, aggressiveness, generosity, attribution of your actions as being self initiated, and happiness have been shown to either have a biological basis or correlates. A lot of these functions overlap with what I would have attributed with being the immaterial soul.

For example, I would have thought that trust would be something that would originate in the soul, however, oxytocin can make someone more trusting. It also seems to play an important part of maternal love and long-term relationships. Morality is also attributed to the soul, but alcohol can inhibit moral actions. I don’t see how alcohol can make it more difficult to be moral, unless there is some biological component of being moral. Perhaps, only the conscience is a part of the soul, but acting on the conscience is either a function of the physical brain or a close collaboration between the soul and the physical brain? Also, attributing an action (such as your hand moving) as being self-initiated versus involuntarily initiated (such as uncontrolled shaking of the hand) seems to rely on subcortical areas and people with schizophrenia (presumably a biological disorder) are unable to correctly attribute their actions to themselves. I would have thought that the soul be able to distinguish actions that it initiated? Or does the soul even responsible for initiating conscious actions?

Are there Christian scholars who propose ideas of the different roles that our biological brain and souls play and how do they interact?

Note 1: This question may challenge your preconceived notions of the soul, but it does not challenge the idea that there might be an immaterial soul. I’m just curious about details of such conjectures; detailed to the extent that they might form testable hypotheses. Some of which will inevitably be wrong, there is nothing wrong with this.

Note 2: While the soul may be immaterial, if it affects the biological brain, then it is at least theoretically possible to study it with science. For example, gravity still remains a black box to us. There are hypotheses (such as the graviton), but we don’t really know. But this has not prevented us from studying the effects of gravity and learning a lot from it. Likewise, behaviorists treated organisms as a black box, but that didn’t prevent them from making a lot of discoveries about learning.

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    And Welcome to Christianity.SE! – Affable Geek Feb 20 '12 at 3:15
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    There's a tricky part in this question - while neurobiology gradually creeps closer to understanding parts of the brain, science still has, to the best of my knowledge, no meaningful evidence-based definition of a "soul" - my point: I fear this question pits biology against philosophy, rather than looking for answers within a single field. Meaning: if you are after a philosophy answer, the neurobiology is largely moot; and if you are after a neurobiology answer: first, it is necessary to introduce/define (with justification) the concept of "soul" – Marc Gravell Feb 20 '12 at 6:30
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    @Jonathan I appreciate the edit, and I'll be intrigued by any answers - I'm still a bit unclear (purely in logic terms) how it could possibly be answered though: by definition, if it is measurable it is material, and thus falls outside of the scope - and if it is immaterial it is unmeasurable, so how could it be quantified/qualified beyond idle speculation? Fascinating question. – Marc Gravell Feb 20 '12 at 23:32
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    I really think the premise of this question is flawed, and the example of gravity is misleading (we have observational evidence to believe that gravity exists, and the question there is "how does it work?"). Likewise organisms. Here, the question seems to be the philosophical equivalent of "what are the properties of unobtainium?". All I mean is: all the emphasis on science seems to hide the real, much simpler, question here - of "What is the modern Christian view of a soul?". All the science in the question seems only to confuse things, in that it doesn't seem relevant to the question. – Marc Gravell Feb 21 '12 at 19:50
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    Interesting related information... there is such a thing as Christian Materialism, the wikipedia article needs some work, but my understanding is that some Christian Materialists believe that humans do not have souls, that we will receive eternal life after the general resurection. – aceinthehole Feb 22 '12 at 1:15


Reading trough systematic theology books, I found that Christians hold that the human has two are three parts. The two parts view says that the human is body (material) and soul(immaterial), the three parts folks hold the position that human are body(material), soul(feeling), conscience(image of God, moral center).

Here are two links to books chapters on Google :

Lecture in Systematic Theology by Henry C. Thiessen

Systematic Theology by Wayne Grundem

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  • +1 for the 2 vs 3 part views. Do you know a couple of the main proponents from these two views? The other links don't seem as related, but they do add some. Thanks! – user1331 Feb 22 '12 at 15:25
  • I think I agree with @Jonathan that the 2 vs 3 part perspective is interesting. I personally didn't find the first (main) part as useful, as that seems to be merely an objection to the non-inclusion of the soul in clinical treatment, but: I'm not quite sure what that tells us... modern clinical medicine doesn't usually attempt to treat things it can't first observe/quantify/measure (and evaluate success of said treatment). Except for homoeopathy, of course ;p – Marc Gravell Feb 22 '12 at 15:39
  • @Jonathan edit the answer removed what was not related. And add two links to the book chapter that would explain it. – David Laberge Feb 23 '12 at 11:27

You ask for a view from Christian scholars, so here's one (not mine):

In "Cosmos, Creator, and Human Destiny", Dave Hunt argues that the difference between humans and lower animals is in the brain, but that the brain is just matter, and:

as we will continue to remind readers, matter cannot think

(no basis, evidence, qualification, explanation or research is offered for this assertion, note)

Further, that there is a non-physical intangible element responsible for our thought, distinct from (but related to) the physical matter of the brain, which communicates instantaneously between the the physical universe and the non-evidenced soul existence. This then facilitates eternal existence by outliving physical existence. This non-physical form is then responsible for our thought, emotion, and morality. IIRC, physical/chemical damage is then supposed to interfere with this communication.

Indeed, in his attempt to play down evolution, a lot of emphasis is placed on the difference between man and "lower animals" (which he repeats many times, to draw a very thick line between humans and anything else), which is problematic:

  • a lot of higher primates are very communicative, and have successfully used things like sign language and similar communication techniques (oddly, not too disimilar to things like Makaton, commonly used by speech-impaired children, at least here in the UK)
  • a lot of animals show things like reasoning (problem solving, etc) and empathy (the rats infamously releasing their trapped cage-mates, etc); if that isn't "thinking" I'm not sure what is

Frankly, I'm not sold on any significant difference between how human brains work, versus that of any other animals - other than we've developed it further, as our primary means of survival. I also think the Dave Hunt work here is very sloppy, in terms of going to great lengths to seek any minor gap in evolutionary theory, while failing to offer even one iota of reasoning for the arguments so strongly asserted. From the author's perspective it makes sense: not presenting such means there is nothing for his critics to pull apart. In my opinion it does not make for a strong case, and as such is representative of most of the other views on a soul that attempt to fit themselves into biology.

Fundamentally, there is a problem: there is no actual scientific justification for even speculating at the existence of a non-physical soul, so trying to find scientifically valid explanations for something that isn't even defined is.... problematic at best. Equally, any purely philosophical proposals designed to fit in with current neurobiological knowledge run a risk of "soul of the gaps" (if you will).

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  • I would have commented sooner, but I kept on wanting to address the last paragraph and I wouldn't finish before I felt like I should get back to work :-). – user1331 Feb 22 '12 at 15:46

It is clearly true that chemicals and physical alterations of the brain can affect how we think and feel. So -- assuming we understand the "soul" to be what is or holds a person's thoughts, feelings, and personality -- any theory that says that the soul is completely separate from the physical body can't be right. On the other hand, the theory that our thoughts and feelings can be completely understood in terms of biochemical and electric activity in the brain is not substantiated by evidence, but is an article of faith by materialists. No one CAN completely explain thoughts, etc in biochemical terms. They insist that someday science will advance to the point where we can. Maybe, but "I believe this will someday be proven to be true based on unprovable dogmas that I believe because I find them emotionally satisfying" is a long way from scientific proof.

People sometimes discuss this as modern science challenging an ancient Bible teaching. But a little thought will show that "modern science" has nothing to do with it. Oh sure, we know a lot more about the chemistry of the brain today then people did at the time the Bible was written. But this doesn't address the fundamental question. People in ancient times were well aware that chemicals and physical damage could affect the personality. The people who wrote the Bible knew that alcohol could affect someone's behavior. They knew that bashing in someone's head could affect his behavior. But they still talked about the soul as something distinct from the body. So it's not a new issue.

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    I see what you are saying, and indeed while it is not currently "completely understood", the materialistic stated aim is extrapolating from things that can be clearly demonstrated in terms of strong (and ever-growing) physical/biological evidence, and which is in line with our physical universe. It has nothing to do with either "dogma" or anything being "emotionally satisfying". The "magic/supernatural soul" is asserting a position from zero points of evidence, based on rules outside anything we know in the universe. Which of these positions is due more criticism? – Marc Gravell Feb 21 '12 at 9:34
  • The question is not meant to be about whether or not there is an immaterial soul. Its meant to be more, assuming that there is an immaterial soul, what might it actually do? What can we apply from scientific (and common) knowledge to learn more about it? What conjectures can we make about what it is and what it does? These postulates may be wrong or may be right. Typically, in Science, they are wrong, but the postulates get closer and closer to being right. There is nothing wrong with conjecturing that there is an immaterial soul and Christianity shouldn’t be tied down to one idea. – user1331 Feb 21 '12 at 15:47