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The Rudolf Steiner Archive

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From Crystals to Crocodiles
GA 347

II. On the human etheric body. Relationships between brain and thinking

5 August 1922, Dornach

Good morning, gentlemen. I would like to continue today with yesterday's subject. After all, we can fully understand a subject only if we deal with it in more and more depth.

As we saw last time, an important fact concerning human beings is that they take in nourishment from the earth, and air from the atmosphere surrounding the earth. It is really only because of this that human beings live and develop into feeling and sentient beings. As we saw, they take in forces from the whole cosmos, and it is only through this that human beings can think and thus become truly human. In other words, we must be able to feed ourselves and to breathe in order to become sentient beings. We must also be able to absorb forces out of the entire universe in order to become thinking beings. We can no more become thinking beings by ourselves than we can learn to speak all by ourselves. Human beings can no more think out of themselves than they can feed on themselves.

Let us now look more closely at how these things work. First, let's try to understand the process of nutrition. We take in food that reaches our intestines in a lifeless condition. The lymph glands re-enliven it and the lymph carries it into our blood, which is constantly renewed through our breathing. The blood, or actually the force of the blood, that is the breath, travels along the spinal cord and rises into the brain, where it connects itself with the activity of the brain. You need only look at how the nutrition of children differs from that of adults, and you will be able to understand much about the nature of the human being. As you know, children must drink a lot of milk in the first years of life. In the beginning, they take in nothing but milk. What are the implications of the fact that babies are fed only milk? We can grasp the significance of this only when we understand what milk consists of.

We are usually not aware that milk is 87 per cent water. In other words, when we drank milk as infants, 87 per cent of what we took in was water and only the remaining 13 per cent was something else. Of the remaining 13 per cent only 4.5 per cent is protein; another 4 per cent is fat, and the rest consists of minerals and so on. Basically, what babies take in when they drink milk is water.

As I told you earlier, human beings consist essentially of liquids. In children, the quantities of these liquids must constantly be increased. Children must grow and therefore require a lot of water, which they take in with their milk.

At this point you may say that we might as well give babies only those 13 per cent that are nutritious and for the balance just offer them water to drink. Well, you see, the human body is not equipped for that. What we get with milk is not just 13 per cent of ordinary protein, fat and so on, but all these substances are dissolved in the milk, are dissolved in the water contained in milk. When infants drink milk, they take in the substances they need in a dissolved state. This means that the child's body does not have to do the work of dissolving the fat, protein, and so on.

Remember what I said earlier about nutrition: all the food substances we eat must first be dissolved in the mouth. In a way, nature allows us to take in solid food only as far as our mouths. There we have to dissolve it with our own fluids. The other digestive organs, such as stomach, intestines, and so forth, can only use dissolved substances. Children must first acquire this ability to dissolve solid matter. At first, they cannot do it alone. Therefore, they must receive food that is already dissolved. You can tell how important this is when you consider that infants brought up on synthetic food preparations will be stunted in their growth.

Now you may wonder if it is possible to produce artificial milk, that is, if we dissolved the 13 per cent solids, such as protein, fat and so on, in water so that the solution would look like milk, would it be equivalent to the milk children normally receive? You see, gentlemen, it would not be equivalent. If an infant were given such artificial milk, its development would be stunted. And since people produce only what is needed, one would have to give up the production of such milk. This synthetic milk would be harmful.

What is it that alone can bring about this dissolving of substance that the child needs? Only life itself can do it. The animals can do it to an extent, but not all of them. At the beginning of life, babies cannot dissolve protein, fat, and so forth. They depend on having these substances dissolved for them in the proper way. Thus they actually receive proper nourishment only through mother's milk.

Of all animal milk, that of the donkey most closely resembles human milk. When an infant cannot be breastfed, it can be fed with donkey's milk. This may appear strange; however, the fact is donkey's milk most closely resembles human milk, and in the absence of the latter one can keep a donkey mare in a stable and thus supply the infant with milk. Of course, I mention this only as a hypothetical situation in order to illustrate how things are connected in nature.

For instance, if you compare the nutritional value of milk with that of a chicken egg, you find that the egg contains approximately 14 per cent protein. That's a lot more than we find in milk, actually four times as much. By the time children are fed such solid foods that contain more protein, they must have developed the capacity to dissolve solid substances on their own.

From these facts you can see how important it is that children get liquid nourishment. But what kind of liquid food? Food that has been filled with life and that, if possible, still contains life forces. This is provided only through breast-feeding by the mother.

When infants drink milk, it passes through mouth and oesophagus into the stomach. In this process, the milk loses its life; it is killed, so to speak, but it is then re-enlivened in the intestines. Thus we see already in children that life must first be destroyed. Since the living food has undergone only little change, infants need to exert less digestive effort for re-enlivening milk than for any other food.

This also shows us something else. If we think about this matter in the right way, what do we notice? Let us think in the right way here. As we said, infants must take in living nourishment, which is first destroyed and then re-enlivened. Now, human beings consist largely of liquids, but can we therefore say that they consist of water, the water we find in lifeless nature? If this were so, the water we find in lifeless nature around us should be able to work in children in the same way it works in adults, who, after all, have gathered more life forces. Here we see that the almost 90 per cent water we have in our bodies is not the ordinary, lifeless water we find in nature; it is a different, an enlivened substance. In other words, what we have in our bodies is a unique fluid: it is enlivened water. It is like the water we find in lifeless nature but filled with the life forces that penetrate the entire world. However, these forces are as little active in the lifeless water in nature as thinking is in a corpse. Therefore, when you speak of water in a creek and water in the human body, you will understand the difference between them if you think of the water in the creek as the corpse of the water that is in the human body.

Thus we can say that in our bodies we have not only lifeless, physical matter but also a life body. This is where correct thinking will lead us, to the insight that every human being has a life organism, a life body. When we study the relationship of the human being to nature, we can see how this organism functions within us. We must first study nature and then look at the human being. When we study nature, we find just about everywhere all the substances we have in our bodies. The only difference is that we have processed these natural substances in our own particular ways.

We'll understand this better if we study the smallest creatures, one-celled organisms. As I describe them, you will see that I am speaking of these smallest and least developed creatures in nature in the same way I spoke of what is inside the human being. You see, in the ocean there are very small creatures. They are actually nothing but small gelatinous lumps, so small that one can see them only with a strong magnifying glass. I will draw them for you, enlarged of course [see drawing below, left part]. These tiny gelatinous lumps float in the water.

gelatinous lumps

If there were nothing but these small lumps and the surrounding water, they would be at rest. But if a small grain of some substance approaches [see drawing above, right part] this creature expands its gelatinous substance until its body fluid envelops the grain. Of course, when it expands its substance, the little lump moves in the direction of the grain. This is how the small lump moves. In other words, by the very act of enveloping a tiny grain of another substance with its own body substance this tiny creature moves. Then it will begin to dissolve the grain inside its body. Thus, this one-celled creature has eaten the grain.

These organisms can of course eat several such tiny grains. Imagine we saw a creature here and a grain there, and there another one and over there two more [see drawing below]. The tiny organism will now stretch its feelers this way and that way. The direction in which it extends most, where it encounters the largest grain, that is the direction in which it will move, pulling the other extensions along. This organism moves by feeding at the same time.

stretching organism

Well, gentlemen, when I describe how these small gelatinous lumps move around in the ocean and feed at the same time, you will remember my description of the so- called white blood cells in human beings. At first glance we realize that they do the same thing inside us; they float in our blood, moving along while they feed, just like those small lumps I described. We understand what it is that moves around in our blood when we look at the one-celled creatures that float in the ocean. We bear such creatures within us.

Having understood that in a certain sense we have the same organisms floating around in our blood that we find outside in nature, let us now look at the nervous system, particularly the brain. The brain also consists of very small particles. When I draw these smallest parts, we realize that they, too, consist of some kind of lumpy, thick, and slimy substance. Several extensions consisting of the same substance radiate outward from this slimelike matter [see drawing below]. When we look at such a brain cell, we see that it stretches out its tiny feet or arms and touches those of the neighbouring cells. These cells can be very long; some extend almost through half the body, and each one of them is again located next to others. When we study the human brain under a microscope, it appears like a number of dots in which the slime-like substance is more densely concentrated. Thick branches extend from there and intertwine. If you imagine a dense forest with thick tree crowns and big, interweaving branches, you get an idea of what the human brain looks like under a microscope.

intertwined organism

Now you may say, all right, we have just heard a description of these white corpuscles living in our blood. The brain has been described as very similar; it, too, consists of many particles such as those we find in the blood. Thus, if we could remove all the white corpuscles from the blood without killing the person, and if we could put them neatly into the brain, after having removed that also, then we would have created a brain for that individual out of his or her own white blood cells.

However, the strange thing is that before we could create a brain out of these white corpuscles, they would have to be almost dead. This is the difference between the white blood cells and the brain cells. The white corpuscles are full of life; they move around in our blood. I told you that they surge through the blood vessels just like the blood itself. Then they leave their original habitat. As I mentioned earlier, they become gourmets and even move all the way to the surface of the body. They move around everywhere in the human body.

In contrast to those cells, you will find that the brain cells always stay in one place. They are at rest. Each one merely extends its branches and thus touches the nearest neighbour. Whereas the white corpuscles are in constant motion, the brain cells are at rest and in fact are almost dead.

Let us think once more of that tiny organism floating in the ocean. Let's imagine that one day it eats too much. It extends its arm, takes in food here and there, and overeats. This is more than the small creature can take, and so it divides; it splits into two. Instead of one organism there are now two. The original one has multiplied. Our white corpuscles also have the ability to multiply. There are always some dying off and others being produced in this way.

The brain cells, which I drew for you, cannot multiply. The white blood cells are full of life, independent life, and they can reproduce. However, the intertwining brain cells cannot reproduce. One brain cell will never turn into two. As the brain grows and increases in size, new, additional cells must move into the brain from the rest of the body. They must grow into the brain. The cells in the brain never multiply there, but merely accumulate. As long as we grow, new cells must constantly move into our head from the rest of the body, so that we have a sufficiently large brain when we are grown up.

The fact that the brain cells cannot multiply already tells us that they are almost dead. They are constantly in the process of dying. When we think about this in the right way, we discover a marvellous contrast in the human being. In the blood, we have cells, the white corpuscles, that are full of life, of a desire to live. In the brain, on the other hand, we have cells that actually have a constant wish to die, that are constantly in the process of dying. Thus it is true that as far as the brain is concerned human beings are in a constant process of dying. The brain is constantly on the verge of dying.

Well, gentlemen, I am sure you have heard of people who fainted, or perhaps you have experienced this yourselves. I know it is an embarrassing thing to experience. When people faint, they feel like they are falling. They lose consciousness.

What has actually taken place in a person who loses consciousness this way? You know, I am sure, that very pale persons, such as anaemic girls, faint very easily. Why is that so? Well, you see, they faint because in proportion to the red corpuscles, they have too many white ones. Human beings must have a certain proportion of white to red corpuscles to be properly conscious. What then does it mean to lose consciousness, for example, in fainting or in sleeping? It means that the white corpuscles are too active. When this happens, we have, as it were, too much life in us, and as a result we lose consciousness. Therefore it is very good that we have cells in our head that have a constant desire to die. If these white corpuscles in our brain, too, were to be very much alive, we would not have any consciousness at all, but would always be asleep.

Now you may want to ask why plants are always asleep? Well, this is because they don't have such living organisms within them. Actually, they have no blood at all and therefore do not have this independent life that we bear within us.

If we want to compare the human brain with something similar in nature, we must look at plants. In fact our brain constantly undermines the life we have within us, thus creating consciousness. Our understanding of the brain leads to a paradox. There is indeed a contradiction in the fact that the plant has no consciousness, but human beings do. This is something we can explain only after long and careful thinking, which we will begin now.

As you know, we lose consciousness every night, when we sleep. Clearly, something is going on there in our body that we must now try to comprehend. You see, gentlemen, if the same processes were taking place in the body when we sleep as in the waking state, we would not be able to sleep. When we sleep, our brain cells begin to be a bit more alive than when we are awake. In other words, they then begin to more closely resemble those cells that have an independent life inside us. Picture it like this: when we are awake, our brain cells are completely at rest; when we are asleep, they still cannot move around, because they are held in place, and cannot float around, for they would immediately come up against obstacles. Yet one could say that they now summon up the will to move. The brain thus becomes restless. Because of this inner restlessness of the brain we become unconscious when we sleep.

Now we must ask how human thinking originates. How is it that we are able to take in forces out of the entire universe? With our digestive organs we can absorb only earth forces in the various substances we take in. With our respiratory organs we can absorb only the air, in the form of oxygen. In order to take in all the forces of the entire universe, the head must be at rest. The brain must be completely at rest. But when we sleep the brain begins to be restless; then we take in fewer forces from the universe and lose consciousness.

But there is more to it than this. Let's assume some work is being done at two different places. For instance, here it is done by two men and over there by five. The parts they produce are then assembled later. At a certain point it becomes necessary to reduce the amount of work in one place because too much was produced there, and in the other place not enough parts were made. What do we usually do in such a case? We ask one of the five workers to join the other two. Then we have three workers at one site and only four at the other. Thus we shift some of the work around if we don't want to increase the output.

Similarly, human beings have only a limited amount of forces or energy at their disposal, and they must distribute them carefully. The strength required to increase the brain activity when we sleep must be withdrawn from other areas of the body. Where is it drawn from? It is withdrawn from some of the white blood cells. Some of them are less active when we sleep. The brain becomes more active when we are asleep, while some of the white blood cells become less lively. This is the compensation I spoke about before.

Remember, I also said that because the brain is less alive and comes to rest, human beings are able to think. Since the white corpuscles are more at rest during the night, we should actually begin to think. We should be able to think with our bodies.

Is it possible that human beings think at night with their bodies? That's a tricky question, isn't it? All we can say at first is that we are certainly not aware of it. However, that we are not aware of something does not necessarily prove that it doesn't exist. If it did, then everything we have not yet seen would also not exist. Indeed, the human body may think at night for all we know; since we are not aware of it, we would have to deny it.

Now let's see if there are any clues indicating that while we think with our heads during the day we may actually think at night with the liver, the stomach, and the other organs, perhaps even with the intestines. In all of us there are certain indications that this is indeed so. Just think how it is possible that something exists even though we are not aware of it. For instance, while standing here and talking to you, I focus my attention on you, and that means that I am not aware of what is going on behind my back.

This can lead to strange incidents. For example, during these lectures, I may be in the habit of occasionally sitting down on this chair. While I focus my attention on you, someone removes the chair. I cannot see it happen, but happen it did. I will certainly become aware of the effects as soon as I try to sit down! You see, we must judge things not only on the basis of what we normally know, but also on the basis of what we may know indirectly. If I had just happened to look back quickly, I would probably not have sat on the floor. If I had taken a look, I would have avoided doing that.

Let us study thinking as it occurs in the human body. You see, scientists love to talk about the limitations of human cognition. What do they mean by that? They mean that whatever they have not yet seen—with the naked eye, the telescope, or the microscope—does not exist. But to suppose this is like continually sitting on the floor by mistake—for not seeing something happen does not mean it hasn't.

In order to become aware of something, I must not only think about it but also observe what I have thought of. The thinking going on in me may be a continuous process, sometimes occurring in the head and at other times in the entire body. But when I am awake, I have my eyes open. The eyes do not only look outwards, but also perceive inwardly. Similarly, we do not only taste food in the mouth, but also perceive inwardly that, for instance, the body as a whole is ill and therefore something otherwise delicious is now disgusting to us. In fact, this inner aspect is always the determining factor. This perception of what goes on inside us is as essential as the perception of what is outside us.

Imagine you wake up as usual. Your brain cells gradually slow down their activity and come to rest, and you can begin to use your senses again. This normal way of waking up, completely in accordance with the normal rhythm in life, is one way of waking up. However, it is also possible that for some reason your brain cells come to rest too abruptly. Then something else happens. Going back to the example of the workers, let us imagine that the person in charge of a project sends the fifth worker from one site to join the other crew. Under certain conditions, this may work out very smoothly. However, let's assume that there are two foremen. One of them must remove a worker from the one site and the other one must put him to work at the second site. This may not work out so smoothly, especially if the two supervisors argue about whether or not this is a good idea. Similarly, if the brain cells come to rest abruptly, the white corpuscles which were inactive during sleep may not be able to function again so quickly. So it may happen that while the brain cells are already at rest again the white blood cells are not yet ready to get up. They insist on getting some more rest and will not get up.

It would be marvellous if we could directly perceive these lazy blood corpuscles that, figuratively speaking, want to stay in bed. We would then look at them as we normally look at the brain cells and perceive the most wonderful thoughts in them. At the very moment when we wake up too abruptly, we would then perceive the most marvellous thoughts. We can understand this easily, gentlemen, if we look at the connection between the human being and nature. If nothing else interfered and we woke up abruptly, we would perceive the most marvellous thoughts in our body. However, we can't do that. Why is this so? You see, between these lazy, sleepy white blood cells and the perceiving organs in the head occurs the entire process of breathing, which involves the red corpuscles. Breathing is a continuous process, and we must therefore study the thinking processes in the whole breathing process.

Imagine you are waking up and your brain comes to rest. In your blood there float some white corpuscles. If you could perceive them when they are at rest, you would see the most beautiful thoughts in them. However the entire breathing process is also mixed up in this. This is as though you were looking at something through a cloudy piece of glass; everything will be blurred and nebulous. The breathing process is like the cloudy piece of glass; it blurs the thinking going on in the body below the head. This is what then gives rise to dreams. Dreams originate from the vague thoughts we perceive when the nightly activity of the brain cells comes to rest too abruptly.

Something similar happens sometimes when we fall asleep. The brain may become active too slowly and still have the ability to perceive something when thinking in the body is already beginning. Then we can observe this thinking as we fall asleep. We are not aware of these inner thoughts for most of the night, during deep sleep, but while we are falling asleep or waking up, we can perceive them in the form of dreams. And we actually become aware of dreams only at the moment of waking up, as you will see when you study a dream carefully.

For example, let's say you are sleeping, and there is a chair next to your bed. Now you dream that you are a student at a university and one day you meet another student. There is an exchange of angry words, and you insult him. He cannot ignore the insult and must react, and challenges you to a duel.1 Well, you dream all the other details. The two of you select seconds and walk out into the woods. Then you start shooting; there is the first shot. You hear it in your dream and wake up. Then you realize that you merely knocked over the chair by your bed. That was the shot you heard!

Well, gentlemen, the entire dream would not have occurred if you had not knocked over the chair. The dream developed as it did only at the moment of waking up, for after all it was the falling chair that woke you up. In other words this picture, the blurring of what was going on inside you, came about only at the moment of waking up. This shows you that the pictorial element of dreams can only be formed at precisely the moment of waking up or falling asleep.

When we form such pictures and can perceive something in them, we must also have thoughts about them. Where does this insight lead us? It brings us to some understanding of sleeping and waking. Let us ask then what sleeping really means. When we sleep, the brain is more active than when we are awake, and it comes to rest when we are awake. You see, gentlemen, if we were to say that the brain is more active while we are awake, we would be materialists, for we would then equate the physiological activity of the brain with thinking. But if we are sensible people, we cannot say that the brain is more active in the waking state than in sleep. It must come to rest when we are awake.

Therefore the physiological activity in us cannot lead to thinking. If it could, thinking would have to result in a stronger physical activity than the non-thinking phase. However, it is the absence of thought activity that is accompanied by an increased physical activity. Therefore we can say that our lungs would be lazy and inactive if oxygen from the outside did not reach them and activate them. Similarly, the brain is lazy during the day, and consequently something must reach it from the outside and activate it. Just as oxygen activates the lungs, so something coming from outside the body, something that is not in our body, must reach the brain during the day and initiate thinking there.

We see here that proper scientific thinking leads us of necessity to assume the existence of non-physical forces, of soul forces. After all, we have just seen that they exist. When we wake up, we see them move into us, as it were, for thinking cannot come from our bodies. If it could, we would necessarily be able to think much better at night. Thinking would then begin after we lie down and fall asleep. But that s not what happens. Rather, at the time of waking up, we sense something move into us: our soul and spirit being.

Granted, science has made considerable progress recently. However, it has learned only about things that are unsuitable for life itself and for thinking. Science has not understood life itself, and thinking even less. If we pursue natural science in the right way, it will be this true science, not some sort of superstition, that leads us to the realization that just as there must be oxygen for the breathing so there must be something spiritual for thinking.

We will go into this again next time because it is not a simple matter. Many of you will object strongly to what I have just said. But those who say something different do not comprehend what is really going on in the human being. It is therefore not a question of spreading some kind of superstition, but of establishing a clear understanding. That is what really matters.