Plato on how the brain and body influence each other

As I said last time, Plato takes up the Homeric concepts of ‘psyche’, ‘thymos’ and ‘phrenes’ and develops a detailed theory with various similarities and differences to the originals. I also explained that Plato realized that if we could figure out how the living body of a being registers stimuli, it would go a long way toward us understanding how the more intelligent system, the perceptive consciousness of a human, works. He originally set out his theory in his classic Republic (audio), but he offers an extended, more ‘scientific’ discussion of the interplay between mind and emotion in the Timaeus.

His major theoretical development is to talk about the mind as having a tripartite nature, and argues that it is this that allows us to move beyond the child-like behavior of the Iladic people. Upon thinking about human capabilities and behavior, Plato argues that it seems certain that unlike merely conscious animals, humans depend upon two “mental’ systems to live and interact with the world. One is found throughout the body, focused in the chest, and the second is localized at the brain and interconnected with the first one.

Let’s call the first, more basic system ‘body-psyche’. It is basically what today we’d call the central nervous system and its job is to take in the literally “necessary disturbances” of life, such as pleasures and pain, while also being the source of others such as boldness, fear, anger and expectation. Note that all of these are tools necessary for dogs as well as humans to survive, and they are at the core of the ability to socialize. The mental activities of the body-psyche are still aligned closely with simple ‘unreasoning’ awareness (e.g. lusting).

Plato notes, however that humans can sometimes overcome lust and other such unreasoning awareness, but other animals, such as dogs in heat, cannot. This leads Plato to say that the body-psyche appears to be ‘separated’ from the other psyche, the one capable of reasoning, as if by some barrier.

But what is this barrier, what distinguishes the brain-psyche from the body psyche? Plato answers that it stands to reason that something in or about the (human) brain allows for our ability to sometimes overcome unreasoning awareness. (And he thinks, somewhat naively, that it’s quite important that the brain is geographically separated from the rest of the ‘mind-system’ by the neck.)

At this point you may be thinking this two-part distinction is pretty clear cut and are wondering how he’s going to find a third “part” to distinguish. Plato thinks it overly simplifies what is going on, but to move forward he has to write you a check and promise to cash it a little later. He asks a series of probing questions: Do we as a matter of fact note any mental activity at all that is neither pure reasoning nor unreasoning awareness? Is it is possible to explain how such activity is created physiologically? Is there any benefit to pursuing this speculation? He answers “yes!” to all of these.

Getting a better view

Let’s take a step back to look at what is going on here, what Plato is doing. He is in the business of trying to understand how simple awareness and perceptive consciousness work and linking them to higher cognitive functions such as abstract thought. He’s committed to a physiological relationship between them that runs: registering (seeing, hearing, feeling a thing)à consciousness (being aware of and paying attention to the thing) à higher cognition (reasoning about the thing).

So we think that there’s more to the story about perception and mentality than the Iladic story can explain and we’ve got the brain-psyche on one hand and the body-psyche on the other. Plato then stipulates that the bodily psyche itself has two parts. The superior part of the bodily psyche has the following properties: it exhibits “spirit” and ambition; it is physically closer to the brain; it can and does listen to and work with reason; it forces compliance from the (lower) part of the body-psyche that consists of appetites, as for food and sex.

Plato gives a lot of reasons why human physiology supports this view. To show the reality and power of the ‘lower” body psyche, he notes that no humans, in fact no animals at all, could exist if the appetite for things the body needs such as food and rest were not 1) sustained and continual and 2) strongly felt. In fact, this set of necessities we call appetites constantly need satisfaction; I’m sure you know how hard it is to think straight when you’re starving or really have to relieve yourself. Further, when we look at how the heart works and how we can raise and lower our heart rate, we get an idea of how ‘reason’ can use the body to exert its will on the body.

To better explain what the “superior” bodily psyche is, Plato says that by and large the appetites don’t “understand” the deliverances of reason and to the extent they do, they have no innate regard for reason. Instead, it appears to common sense that appetites are enticed – and so controlled – by “images”, they react immediately to what they see. However, the superior body psyche, which I can now tell you is the emotion center, clearly does respond to reason. After all, many people, probably even you, have appetites or desires for things that you wish you didn’t. In fact, many people have desires for things that they really are embarrassed by, and they get really mad at themselves for indulging them. So mad, even, that they often can force themselves to stop. Plato thinks that the fact you can be aware of, judge negatively, and cease to act on an appetite is evidence enough that the reasoning capacity can work in concert with something – the emotions – to control the appetites.

Now the details of the physiology Plato gives us as to how this works are not very useful so I’ll bypass them, and happily, his psychological theories are not dependent on the details. He’s not working from the way the organs actually work and building out a psychology that fits on top. Instead he starts from experience and behavior and is looking to see if there’s a plausible way to account for his theories based on human physiology.

It is useful is to note that he was trying to meet the scientific data he had and at the same time answer a difficult problem as honestly and intuitively as possible, with as much explanatory power as possible. His conclusion was a psychology that says mind consists of three “parts” the psyche which is capable of abstract thought and can control the body, the thymos or “spirited” part, which is our emotion center, and the phrenes, which Plato casts as the appetitive part.

Cashing the check

Remember the end point we’re working towards: Plato thinks we can better understand the mind and human behavior if we move beyond the simple views that our minds are our thymos and that all mental activity is like that of the Iladic people or children, a sort of “hot thinking”. He believes that we can gain great explanatory power from looking at human mental capacity as consisting in three physically interconnected “parts” that will account both for hot thinking and cooler thinking, and that based on how human physiology is set up, the how behind the things this theory suggests happen is plausible. Here’s a high-level synopsis:

1. In humans as with other animals, appetites or desires typically run on their own. All things being equal, when an appetite strikes, humans, like other animals, ‘mindlessly’ pursue it. This much covers how any animal conscious being comes to feel pleasure and pain, and how they affect action. But Plato also wants to explain how humans are not only animal conscious but self conscious and how the two are related.

2. Sometimes, instead, in humans the emotion center (thymos, or superior body-psyche) communicates to the appetites what our reasoning part wants done about a situation, such as whether or not to pursue satisfaction as well as how better to do so.

3. Whatever the communication between these parts is done with, it must be a way that is ‘understandable’ for the appetites. It appears to be a physical messaging system that uses various bodily fluids to affect the vital organs such that the body can be put into various states such as pain and nausea, which have a very strong influence on the will or the desire to pursue a course of action. In fact, these states are strong enough to undermine the otherwise very strong urge to satisfy a currently active desire and replace it with another one supplied by reason.

4. The reasoning part of the mind, in conjunction with the emotions, is able to manipulate the proper physical changes in the body, thus sending the proper message of pleasure or pain to silence (or strengthen) the basic pangs that are messages of appetite. Of course these appetite messages can also be very strong and overpower the inclination to do things that require intelligent thought. These messages go back and forth between the body and the brain, with varying degrees of success. (Going forward we’ll refer to this process as duplex communication).

5. For example, let’s say you have the desire to do something you think is awful, like kicking a puppy that’s been yapping for too long. You kick it and realize the poor thing was just looking for attention and now you’ve seriously hurt it and as you get a sick ‘guilty’ feeling in your stomach, the anger you felt about the yapping disappears, along with the desire to punish the animal, you feel sorry and promise to yourself never to needlessly attack a defenseless animal again.

To strengthen this idea of duplex communication, Plato argues that its clear that bodily conditions can cause illnesses in the brain-psyche, thus stopping it from working as it often can to control our behavior:

1. "Mindlessness": Either ignorance or madness. In the first case, your physical need to eat or to go to the bathroom can become so strong that you are no longer aware of your surroundings. In the second, you literally lose touch with reality due to things such as lack of sleep or syphilis.

2. "Excessive pleasure or pain": too much of either leads to an inappropriate level of exertion, which undermines the ability to hear anything correctly. Think of an addict, of drugs, sex, video games, attention or whatever. They like the thing too much, such that they focus way too much energy on obtaining it and they can’t ‘hear’ things such as the demands of their body, their boss, spouse, friends, etc.

In the next post I’ll give a more detailed discussion of these three parts of the mind, and further explain the benefits of the view for understanding the connection between the emotions and morality.

Moving on from Homer

Recapping up the discussion of Iladic people

Let’s recap on what the mental lives of the Iladic people were like. These people didn’t distinguish well at all between ‘thinking’ and ‘emoting’, and used the concept of the physical ‘thymos’ to characterize both. The thymos, you’ll recall, did the things we now take to be done by the brain and CNS; it was effectively the ‘mind’ and its various functions, and was literally thought to be a mixture of breath and blood located in the lungs (phrenes).

We also saw that based on this understanding of mind, Onians explained that learning was as literally “taking into the mind” and forgetting was literally “letting escape”. In addition, the state of a person’s thymos was thought to determine the “fierceness, energy and courage of a person” and the emotions were physical events or things that “enter into” the thymos as a liquid enters a cup.

Finally, let’s recall that we said that for Iladic people, perception or cognition was automatically associated with an emotion, and immediately followed by some degree of a tendency to action. By contrast, we today, and even Greeks of the classical era, exhibit the ability to seemingly “think in cold blood”. We’ve attained more discrimination about what’s going on in our minds, we’ve identified and defined various aspects and phases of mental activity rather than understanding mental activity as all of a piece.

To our credit, over the centuries we’ve managed to use language and abstract thinking, as well as philosophical and scientific examination, to slice and dice what our bodies do when we think and emote, and we’ve clearly become “outwardly more restrained” and even “inwardly calmer” in our actions than the Iladics are represented to have been. Much of this is to the good. Yet at the core of our advancement was a turning away from the core premise that all human mental life is physically based.

Quite some time ago we began forgetting, ignoring, or rejecting the basic starting point that emotions and thinking were coming from the same place, and in our efforts to locate more exactly what was the source of our mental lives, we made emoting and thinking functions of different parts of our anatomy, while at the same time coming to think of these different parts of our anatomy as fundamentally different. And even though most people today working on issues in and around cognition do accept that all thinking and emotional activity is physically based, you may be surprised to find out that old biases have calcified and we’re left with a big mess. At the core of the mess, as Joan Wynn Reeves put it, is the typical modern psychological view that there are “sharp distinctions between thought and feeling”.

More on that in the future, now let’s meet Plato.

Plato, or The Source

My argument is that if you look at Plato, Aristotle and Lucretius with a charitable, reasonable eye to what they were trying to address in psychology with the information on physiology they had, we can uncover a conception of mind and emotion that rivals any we have available today. This “P-A-L” account shows us that while a visceral view such as that of the Iladic people is useful, strict adherence to such a view is simply not robust enough. The account also provides a foundation on which to build a theory robust enough to handle the actual complexity of the relationships between mind, thought, emotion and morality. Unfortunately, it wasn’t long after Plato and Aristotle that theories about the emotions started off on two quite debilitating forks from this promising path.

I spent much of my discussion of Homer and the Iladic people focusing on thymos because that is overwhelmingly the concept their psychology depends on. However, there were other concepts and terms used for ‘mind’. The most recognizable of them is ‘psyche’, which you’ll recognize as the root of the English word ‘psychology’. In Homer, by and large it refers to “life-soul”, usually identified with spinal fluid or seminal fluid, which the ancients though literally gave life to a being. Through the ages between Homer and Plato the concept of thymos evolved and changed and distinctions were made that moved the “psyche” from this sort of spinal-seminal fluid to the immortal soul and the “seat of rationality”. For example, the poet Pindar (or II) is said to have developed the meaning of psyche into something “divine” and in some sense “concerned in the feelings of ordinary waking life” but at the same time “asleep when the limbs are active”. Plato, while he accepts the basic Iladic position that thinking and emotions come from the same physical system, significantly develops all of these concepts.

One thing I want to point out that is consistently overlooked is that Plato thinks the physicality of cognition is invaluable. People point to his theology (II) and metaphysics and overstate Plato’s wish for dissolution of the bonds between mind and body. As far as his psychology is concerned, it’s simply not important. We’ll see that what is crucially important is his creation of the conceptual space, the theoretical framework, for excluding some mental activity, sometimes, from the intrusive, inevitable and even overwhelming forces acting in and on the human body.

The Basics on Plato’s Adjustments

Plato starts from the view that in early childhood development (II), we are all like the Iladic people: everything takes a back seat to our immediate desires and our actions are based on the immediate information we have available. Our body is the conduit of information about both internal physical states (e.g. grumbling stomach, pain in leg) and external events that cause changes in our internal physical states (e.g. being hit by an object, a parent’s voice). Our responses to these states are limited to hardwired reactions. We slowly move beyond inborn or built-in responses to these states up to basic intelligence through experience and increasing body control.

Plato notes that we only perceive a limited amount of the information given us; some thing, some mechanism, filters the constant flow of stimuli. Its hard to overstate the importance of this move by Plato. It allows for a psychology that can distinguish between the center of registration and the center of perception. The center of registration is effectively the living body of any being and the center of perception, of consciousness, is a living body with a working psyche. The center of registration is the more basic system, it underlies all thinking and self consciousness.

After making this crucial move, Plato realized that if we could determine how the living body of a being registers stimuli, it would go a long way in understanding how the more intelligent system, the perceptive consciousness of a human, works, because they are causally connected. As I’ll highlight as we go along, this realization by Plato is of the utmost importance and the failure of later thinkers to make it is the cause of many problems for later theories of the emotions.

I’ll wrap it up for this post by noting that we only get more abstract thinking ability if we are properly educated. But once we begin learning to use abstract concepts we begin to develop judgment and our actions go from being more or less predictable or determined reactions, like an animal’s, to being actually willful (chosen, intended) acts.