In our first episode (CotB – P1), I provided a rudimentary overview of the major parts of the brain and how thoughts and feelings are transmitted. Hopefully, the explanation was more illuminating than obfuscatory; if not, let me know and I’ll try to do a better job (i.e., I’ll go back and re-do the post). Assuming that everything is sufficiently clear, however, let’s plunge ahead to the second of the issues to be examined.

So we have a brain. Now what?

Well, now the question is: what causes brain activity? The answer is threefold, but only the last one is of interest to us for the purpose of this discussion.

The first two sources of brain activity are external and internal stimuli. The brain is activated by external stimuli whenever our senses detect something in the environment, i.e., in the external world. Looking at this blog is triggering your optic nerve, which in turn is setting in motion a host of dynamics in the brain that result in such things as recognition that these curious little markings are letters and that these letters form words and sentences and paragraphs that are supposed to be a coherent thought.

Brain activites outside the realm of consciousness or awareness also occur. Your eyes move back and forth across the page without you having noticed (until now) or having told them to do so. This is a result of learning, and there are some strong pathways in your brain that cause your eyes to move from left to right and up and down in order to see what the next word is going to be.



At the same time, the stimulation of the optic nerve may result in other, unexpected things happening – such as yawning, or a sudden craving for coffee or something else to do besides read this.

Internal stimuli are triggers that are independent of the environment. For example, when your stomach begins to contract because it no longer has enough food – or, if not food, then something from McDonald’s – when that happens, then it sends a message to your brain (via neurons and the nervous system) to do something about it. When you do finally shove something into your mouth, other things begin happening: saliva is produced, swallowing is activated, your stomach is happy (but doesn’t stop with the signal just yet), blood is re-allocated, etc.

Your body is a busy, busy place, always doing things – like breathing – that are usually outside your awareness. And some things that are always outside your awareness (try, right now, to be aware of what your inner ear is actually doing at this very moment as it keeps you from falling over as you read this). You can perhaps be aware of the effects of some of those activities, but you can’t sense it happening unless something goes wrong.

In our discussion, however, it is the third stimuli that is of primary interest. This third activator of thought, feeling, and behavior is the human spirit. Our human spirit is what enables us to think about things that have nothing to do with our immediate environment or physical existence. It is responsible for the capacities to will to do something, to meditate, to think original thoughts, to create new associations or connections between old networks or constellations in our brains.

The human spirit is not the electrical or chemical signal or transmission within the brain, but is a spiritual dimension of our makeup that instigates such activity.

The human spirit is also that which gives us what the psychologists call temperament, or our particular predispositions in life. Temperament is described by terms such as introverted or extroverted, dominant or compliant, active or passive. It is said that temperament is roughly 50 percent of who we are, although I have no idea how anyone can come up with such a figure.

I would further argue that personality resides in our spirits and that the makeup of the mind (the subject of the next post) is largely the resulting configuration of our brains growing out of the accommodation, assimilation, and compensation due to the interaction of our spirit, our physical constitution, and our experiences.

I believe this because of the Incarnation. When the Second Member of the Godhead took human form, He did not develop a personality that was different than what it had been previously. God doesn’t change, remember? So who Jesus was is who Jesus is and is who Jesus will always be. His Spirit took up residence in human form – He became actual flesh and blood – and it was His Spirit that manifested itself through His brain, mind, and body.

Unlike Jesus, of course, our human spirits are not pre-existent but are formed at the moment of conception (naturally, I believe, not by a direct act of God). Our personalities are largely set at that time, although modified later through experiences, drugs, or by coming in contact with rapidly moving blunt objects aimed at our heads.

Our human spirit not only initiates brain activity but also supervises or superintends conscious thoughts, feelings, and behaviors. Our spirit decides how to respond to some of the external and internal stimuli we experience, and then “accompanies” the transmission at various points along the way. Ideally, at significant points, our spirit can make a choice about which direction the thought, feeling, or behavior will go.

Because we have a human spirit, we are morally responsible. By and large, we can make choices about moral matters.

Next: The Mind


2 Cor 1:13