by Rudolf Steiner
A lecture given in Munch on Jan. 8, 1909 – from stenographic notes not revised by the speaker (GA 68)
Translated by Maria St. Goar (revised)
In the past I have spoken here on a variety of subjects concerning spiritual life. It may be permissible today, therefore, for me to touch upon a more prosaic theme from the standpoint of spiritual science. Problems of nutrition undoubtedly offer a more mundane subject than many we have heard here. It will be seen, however, that particularly in our age spiritual science has something to say even concerning questions that directly affect everyday life.
On the one hand, spiritual science stands accused, by those who know it only from the outside, of aspiring too loftily to spiritual realms, thus losing the firm ground under its feet. On the other hand, the opposite can perhaps also be heard again from those who have become acquainted with spiritual science or anthroposophy through only a single lecture or brochure. This consists in the statement that anthroposophists are entirely too concerned with, and talk too much about, questions of what they should eat and drink. In some respects these critics might well be called idealists in that they believe they view the common aspects of life from a certain exalted level. They raise this objection particularly by taking a stand that can be expressed in the following way. “What man eats and drinks is unimportant. It does not matter what food one takes, rather must one rise above the material dimension by the strength of one's spirit.” Even a well-intentioned idealist might level this objection against anthroposophists.
Well, at a time when these questions are being widely discussed from other angles, it might be interesting to hear what spiritual science has to say about them.
It was a German philosopher, Ludwig Andreas Feuerbach, to whom the phrase, “A man is what he eats,” is attributed. Many thinkers of consequence have agreed with Feuerbach that what man produces is basically the result of foods ingested by him and his actions are influenced by the food absorbed in a purely materialistic way through his digestion. With so much discussion of eating going on, somebody might get it into his head to believe that man is indeed physically nothing more than what he eats. Now, we shall have several things to say on this point.
We must understand each other precisely as to the purpose of today's lecture and the intention behind it. We are not agitating in favor of particular tendencies, nor are we trying to be reformists. The spiritual scientist is obliged to state the truth of things. His attitude must never be agitatorial, and he must be confident that when a person has perceived the truth of what he says, he will then proceed to do the right thing. What I have to say, therefore, does not recommend one course as opposed to another, and he who assumes that it does will misunderstand it completely. Merely the facts will be stated, and you will have understood me correctly if you realize that I am not speaking for or against anything.
Bearing this in mind, we can raise the question from the standpoint of spiritual science as to whether the statement, “A man is what he eats,” does not have a certain justification after all. We must continually bear in mind that the body of man is the tool of the spirit. In discussing the various functions the body has to perform, we see that man utilizes it as a physical instrument. An instrument is useless if it is not adjusted correctly so that it functions in an orderly manner, however, and similarly our bodies are of no use to our higher organism if they do not function properly. Our freedom can be handicapped and intentions impeded.
When we as spiritual scientists consider our organism, we can ask ourselves if we do not make our bodies unfit for the execution of the intentions, aspirations and impulses of our lives if we become bound by and dependent upon our bodies through an unsuitable diet. Is it not possible to mold the body in such fashion that it turns into a progressively more suitable instrument for the impulses of our spiritual life? Will we lose our freedom and become dependent upon our bodies if we ignore what is the right nourishment for us? What must we eat so that we are not merely the product of what we eat?
By asking such questions, we come to look at the problem of nutrition from another perspective. You all know, and I only need allude to this generally familiar fact, that speaking purely materialistically, people continuously use up the substances that their organisms store and they therefore must take care to replenish them with further nourishment. People must concern themselves with replenishment. What, then, could be more obvious than to examine those substances that are necessary for the human organism, that is, to find out what substances build up the animalistic organism, and then simply see to it that the organism is given them. This approach, however, remains an extremely materialistic one. We must rather ask ourselves what the essential task of a person's food is and in what way it is actually utilized in his organism.
I must stress that what I say about man is applicable only to him, since spiritual science does not consider man to be so closely connected with the animals as does natural science. Otherwise, one could simply state that the human organism is composed of proteins, fats, carbohydrates and mineral substances, and consequently search for the best method to satisfy man's nutritional needs of them. But spiritual science holds to the principle that every material occurrence, everything that takes place in the physical sense world, is only the external aspect of spiritual processes. Indeed, even the nutritional processes cannot be purely physical, but as material processes they are really the external aspects and expressions of spiritual processes. Similarly, man is a unity even though the composition of his physical body appears to be a conglomeration of chemical events.
Our attention has frequently been focused on how the ascent from the purely physical to the spiritual realm can be made. We have often heard that the physical body is sustained by the etheric body.  This is the architect of the physical body, which must not be viewed as if only chemical processes took place in it. We will be wrong if, by observing only the chemical processes, we simply ask in a materialistic fashion what happens to the chemical substances. Beyond the etheric body, we must remember, is the astral body. Through it are expressed the instinctive feelings and in certain respects the various aspects of the soul. When we behold man from the standpoint of spiritual science, we find that his etheric body as well as his physical body are inter-penetrated by his astral body. We must not see only one side but also perceive the astral body beyond the physical. Added to these is the I, the fourth member of the human being. We have the total man before us only when we see in him this fourfold being. Only with the total fourfold man before us can we do justice to the scope of the problem of nutrition. Only then can answers be given to the question of how these four members of man's organism react to the influences of various diets.
Now, you all know that humans eat food derived from the vegetable, animal and mineral kingdoms, and with it they sustain their bodies. Let me emphasizes again for the sake of those who are more narrowly inclined toward the care of the inner life that I am not speaking to mystics nor to anthroposophists who are striving to develop themselves spiritually in particular, but to all men. Men take their sustenance from the animal, vegetable and mineral kingdoms. We must realize that plants represent the direct antithesis of man, and the animals represent the mean between the two. The external physical expression of this contrast is to be found in the breathing process. It is a familiar fact that men inhale oxygen, assimilate it and subsequently combine it with carbon that is finally exhaled as carbon dioxide, while in plants, which absorb carbon to sustain themselves, the reverse is true. In a sense, plants also breathe but their breathing process has a completely different significance for them. Hence, we can say that in a spiritual respect plant and man stand opposite each other.
We can become even more aware of this relationship by bearing in mind the influence of light on plants. The effect of deprivation of light on plant life is well-known. The same light that maintains life in plants makes it possible for us to perceive the light-filled world of our surroundings. Light is also the element that maintains life in plants. This is physical light but it is also something more. Just as there is a spiritual counterpart to everything physical, so there is spiritual light in the physical light that rays down on us. Each time a person rejoices over the brilliance of physical light he can say to himself, “Just as when I see another person and it dawns on me that in this person there lives a spiritual counterpart, so also I can imagine that in light there lives a spiritual counterpart.” Indeed, the spiritual light that permeates the physical sunlight is of the same kind and being as the invisible light that dwells within the human astral body. A portion of the spiritual light that permeates the cosmic realm lives within the astral body. It is, however, physically invisible and in this it is the opposite or complement of physical light.
The invisible light lives within us and fulfills a definite task. We might say that since they are opposites, it is to physical light what negative magnetism is to positive magnetism. We perceive it in its external expression when we realize the relationships existing between physical body, etheric body and astral body, which, in turn, is permeated by the I. It has often been explained that throughout life the etheric body fights against the deterioration of the physical body. Men as well as animals possess an astral body and hence the inner light. Now, the function of this inner light is the opposite of that of external light. When external light shines on a plant, the plant builds up its living organism by producing proteins, carbohydrates, etc. Conversely, the task of inner light is to break down, and this process of disintegration is part of the activity of the astral body. There is indeed a continuous dissolution and destruction of the proteins and other substances that we consume so that these substances are utilized in a sense to direct counter-effects against what external light has built up. Without this activity of inner dissolution a man could not be an I-being, and it is only by virtue of his I that he can have inner experiences. So, while the etheric body is concerned with the preservation of the physical body, the astral body takes care that the food a person consumes is constantly built up and again destroyed.
Without this process of disintegration within the physical body, the astral body, in which the I is incorporated, could not live a full life within the material world. As we have seen, there is an alternating process obtaining between men and plants, that is, exhalation of carbon dioxide in men and absorption of carbon dioxide by plants; exhalation of oxygen by plants and inhalation of oxygen by men. These processes reach such extremes only between people and plants. Animals do not have an individual I as is the case with people, but they have a collective group I. Thus, the animals of a species have one common group I that governs them from without. The significant difference between men and animals is found in the fact that the disintegration processes within animals are directed by an entity external to them, whereas the same processes in men are conducted by their individual inner I. Moreover, a man's individual I can gradually become master over what takes place within him.
Let us consider how the I can gradually take a central position within the bodily functions. Let us examine what the astral body does when it dissolves the substances assimilated by men. In regard to nourishment an entirely different viewpoint must be stressed. The body permeated by the I performs an action in disintegrating substances, and through this action something is created inwardly. The inner activity of consciousness particularly comes about through the astral body's processes of dissolution. Activities are called forth by the process of destruction. First, inner warmth is produced and second, something that is less noticeable than inner body heat which is the physical expression of inner light. Just as the internal warmth that permeates the blood is the result of the dissolution of proteins, so the activity of the nervous system is the expression of this inner light. In regard to its inner activity the nervous system is also a result of the disintegration process; not the nerves themselves but the activity of the nerves, the actions within the nerves, that which makes possible imagination and calls forth thinking. It is this activity that can be called the physical expression of the invisible light which is brought about through the degeneration and dissolution of substances.
Basically, as has been said, inner body heat is generated by the disintegration of protein. Inner light is produced within the organism as a result of protein. Inner light is produced within the organism as a result of processes involving fats, carbohydrates, starches and glucose that are also utilized in the production of warmth and inner movement. In all this is contained the expression of the activity originating from the astral body. People do not nourish themselves properly simply by ingesting the correct quantity of food, but rather when these inner processes can be carried out in the right way. The inner life is founded on them. Men are beings continually occupied inwardly with movement and liveliness and their inner life consists of these. If this inner life is not produced in the right way, it cannot react properly and illness ensues.
The right kind of inner flexibility offers the foundation for the right solution of nutritional problems. This statement points to the fact that all internal processes that men must execute must be carried on in the opposite direction from the processes of plants. A man must begin his processes where the plant processes leave off. A specific example will clarify what this means. When a person eats vegetarian food, it demands a great deal of his organism. Plant food does not contain much fat. The human organism, which is able to produce fats, is thus required to produce fat from something that in itself contains no fat. In other words, when a person eats vegetarian food, he must produce an activity within himself and make an inner effort to bring about the production of fats. He is spared this task when he eats ready-made animal fats. The materialists would probably say that it is advantageous for a man to store up as much fat as possible without having to make too much of an effort. Yet, speaking from the spiritual viewpoint, the unfolding of this inner activity signifies the unfolding of the actual inner life. When a person is forced to produce the forces that make it possible for him to produce fat on his own, then, through his inner flexibility, the I and the astral body become masters of the physical and etheric bodies. When a man eats fat, he is spared the task of producing fat himself. Yet, if he takes the opportunity to use his own inner activity through producing his own fat, he is made free and thus becomes lord over his body. Otherwise, as a spiritual being he remains a mere spectator. Everything that takes place in him in such wise that he remains a passive spectator becomes a heavy weight in him and hinders his urge to let the astral body come to full life. Thus, the astral body's inner flexibility comes up against an internal obstacle if it is denied the opportunity to produce its own fat.
The essential question now to be asked is what internal activities are aroused by what substances. Here we shall try to throw light on the relationships of vegetable and meat substances in human diets, and thereby to gain some idea of the manner in which animal and vegetable foods react in the human organism.
Eating animal protein is not the same as eating plant protein. Up to a certain point the inner processes of the animal are quite similar to those of the human organism, since the animal also possesses an astral body. Even though the animal astral body causes the dissolution of the synthesized substances of its physical body, the human organism carries the processes a bit beyond the limits reached by that of the animals.
In reflecting upon the animals around us and by looking spiritually into their ways and characteristics, we shall, by comparing men with the multitudes of animals, find distributed among the animals the various and manifold characteristics of human beings. In spite of the fact that one can point out great human differences between the various peoples, one must still conclude that each individual person represents a species. Men appear to be the spiritual consolidation of all that can be observed distributed in the various animals forms. If one were to picture all the individual characteristics of the various animal species as being mutually complementary, one would arrive at the essence of what is contained in appropriate moderation in each individual man. Each individual animal one-sidedly contains within itself something of the forces that are harmonized within men, and its whole organism is constructed accordingly. Everything down to the most minute structure of substances is so organized in the animal kingdom that it is like a tableau of human characteristics spread out before one.
If a person is to find the physical expression of the characteristics of his astral body, he must strive to utilize all its forces. He must become master of his own inner processes and activate his astral body in such wise that the plant processes will be continued inwardly. In the food we consume from the animal kingdom, we not only take into ourselves the physical meat and fat of the animal but also the product of its astral body contained in these substances. When, through a vegetarian diet, we enlist the virginal forces of our astral body, we call forth our whole inner activity. In a meat diet part of this inner activity is forestalled.
We can now proceed to consider the relationships of these two types of diet from a purely spiritual basis.
If a person desires to gain an increasing mastery over the inner processes of his body, it is important that he become correspondingly active in the external world. It is important for him to develop certain external qualities such as stamina, courage and even aggressiveness. To be able to do so, however, it is possible that he may not yet find himself strong enough to entrust everything to his astral body and may have to fall back upon the support of a meat diet.
It can be said that man owes everything that liberates him internally to the substances derived from plants. Faculties, however, that enable him to be actively engaged in earthly life, need not necessarily grow out of the virginal nature of his astral body. These qualities can also be derived from a meat diet. This fact that men are to become progressively freer while at the same time needing qualities that they can acquire with the help of impulses found spread out in the animal kingdom, has induced them to resort to nourishment in animal food. If the eating habits of the people of those militant nations that have striven to develop qualities enabling them to develop their physical forces are investigated, it will generally be found that they eat meat. Naturally, there are exceptions. On the other hand, a preference for an exclusively vegetarian diet will be found to prevail among people who have developed an introverted and contemplative existence. These two aspects of the problem should be kept in mind. A person, of course, can adopt either diet as a panacea if he wishes to propagandize rather than to act out of knowledge. Nevertheless, it is not without reason that a mixed diet has become acceptable to many people. To some extent it had to happen. We must admit, however, that even though a vegetarian diet might indeed be the correct one for some people purely for reasons of health, the health of others might be ruined by it.
I am speaking here of human nature in general, of course, but men must be considered as individuals if they are to find the right path to satisfy their needs with a vegetable or meat diet. Today, an extreme diet of meat naturally brings its corresponding results. If by eating meat a person is relieved of too large a portion of his inner activities, then activities will develop inwardly that would otherwise be expressed externally. His soul will become more externally oriented, more susceptible to, and bound up with, the external world. When a person takes his nourishment from the realm of plants, however, he becomes more independent and more inclined to develop inwardly. He will become master over his whole being. The more he is inclined to vegetarianism, the more he accepts a vegetarian diet, the more he will be able also to let his inner forces predominate. Thus, the more apt he will be to develop a sense for wider horizons and he will no longer restrict himself to a narrow life. The person who is fundamentally a meat eater, however, limits himself to more narrow vistas and directs himself more rigidly toward one- sidedness.
Naturally, it is the task of men today to concern themselves with both aspects so as not to become impractical. A person also can be so completely unprejudiced as to have no judgment at all. Still, it is a fact that everything that limits men and leads them to specialization is derived from a diet of meat. A man owes to a vegetarian diet the impulses that lift him above the narrow circles of existence. An extreme diet of meat is definitely connected with man's increasing dogmatism and his inability to see beyond the confines into which he was born. In contrast, if men would show more interest in the food coming from the realm of plants, they would discover that they are able more easily to lift themselves out of their narrow circles. The person who abandons the task of fat formation by eating meat will notice that the activity thus forestalled erects a sort of wall around his astral body. Even if one is not clairvoyant but judges these matters only with common sense, he can tell from the look in a person's eyes whether or not he produces his own fat. It can be seen in the eyes of a person whether or not his astral body is obliged to call forth the forces necessary to produce its own fat.
Now it can be seen how two opposing conditions of character are created when a person takes his nourishment from either the plants or animals. We find that we indeed penetrate into the world through our organism and must again rise above it by means of the right kind of food. A time will come when a vegetarian diet will be valued much more highly than is the case today. Then thinking will be so flexible that men will be willing to investigate such matters knowing that what they believe today to be foolishness could, viewed from another standpoint, also have its merits. They will realize then that their whole physical and spiritual horizon can be widened through a vegetarian diet, thus counteracting the rigor of specialization within them. Particularly in certain areas of science would perspectives be widened if vegetarian diets should become prevalent.
Let me mention a few more examples to demonstrate that men are indeed what they eat and drink.
Consider, for example, alcohol, which is obtained from plants. It would take too long to explain the spiritual scientific reason showing that alcohol produces physically and in an external way from the plant what a man should develop physically within himself through his I centered within him. It is a fact inwardly perceived through spiritual science that when a person drinks alcohol, it takes over the specific activity that otherwise belongs wholly to the person's I. A person who drinks much alcohol needs less food and his body will require less nourishment than is normally required in the process of combustion.
It calls forth forces that otherwise would be called forth by the I's inner penetration. Thus a person externalizes the activity of his I by infusing his body with alcohol. Consequently, alcohol imitates and copies the activity of the I, and you can understand why it is that people turn to it. To the extent, however, that a person replaces his inner self with such a substitute, to that extent does he become its slave. If otherwise qualified, a man will be better able to unfold the best forces of his I when he abstains from alcohol altogether. By drinking alcohol an inner hindrance is created behind which something takes place that actually should and would be accomplished through the activity of the I itself if the hindrance had not been produced.
Some foods have a specific effect of their own on the organism. Coffee is an example. The effect of coffee becomes manifest through its influence on the astral body. Through caffeine and the after-effects of coffee, our nervous systems automatically perform functions that we otherwise would have to produce through inner strength. It should not be claimed, however, that it is beneficial under all circumstances for a person always to act independently out of his astral body. Men are beings who are not dependent on themselves alone. Rather are they placed within the whole of life.
Coffee is also a product of the plant kingdom that externally has raised the specific plant process up a stage. Consequently, coffee can take over a certain task of man. Trained insight perceives that everything in the activity of our nerves that has to do with logical consistency and drawing conclusions is strengthened by coffee. Thus, we can let coffee take over in making logical connections and in sticking to one thought, but this, of course, is in exchange for a weakening of our specific inner forces. What I mean can be seen in the tendency of gossips at a coffee break to cling to a subject until it is completely exhausted. This is not only a joke. It also demonstrates the effects of coffee.
Tea works in a totally different and opposite way. When large quantities are drunk, thoughts become scattered and slight. It might be said that the chief effect of tea is to let witty and brilliant thoughts, thoughts that have a certain individual lightness, flash forth. So we can say that coffee helps those, such as literary people, who need to connect thoughts in skilled and refined ways. This is the positive aspect of the matter. The negative aspect can be observed in coffee table gossip. Tea, which tears thoughts asunder, is the opposite. This is why tea is not without justification a popular drink of diplomats.
It might be of interest to cite as a last example a food that plays an important part in life, that is, milk. Milk is completely different from meat in that it expresses in the weakest possible form the animalistic process brought forth by the astral body of the animal. Milk is only partly an animal product and the animal or human astral forces do not participate in its production. For this reason milk is one of the most perfect foods. It is suitable for people who want to abstain completely from meat but who do not yet possess sufficient strength to work entirely out of the inner forces of the astral body. Even from a purely external standpoint it can be seen that milk contains everything a man requires for his organism. Although this applies only in a restricted sense, it has little to do with the individual characteristics of a person.
Weak as well as strong organisms can gain support from milk. If a person were to live exclusively on milk for a time, then not only would his regular forces be awakened but it would also go beyond this. He would receive from it an influx of forces giving him additional strength. A surplus of forces would be acquired that could be developed into healing forces. In order to possess a force it must first be acquired, and in milk we see one means of developing certain forces in ourselves. Those who are moved by the earnestness of life to develop certain psychic healing forces can train themselves to attain them. Naturally, we must remember that what is suitable for one, is not suitable for all. This is a matter for the individual. One person is able to do it, another not. A man can if he wishes build up his organism in a wise manner. He can contribute toward the unfolding of free, independent inner forces. So through spiritual science we come back to the saying of Feuerbach mentioned at the beginning, “Man is what he eats!”
Man can nourish himself in such fashion that he undermines his invisible independence. In so doing he makes himself an expression of what he eats. Yet he ought to nourish himself in such a manner that he becomes less the slave of his nutritional habits. Here spiritual science can direct him.
The wrong food can easily transform us into what we eat, but by permeating ourselves with knowledge of the spiritual life we can strive to become free and independent. Then the food we eat will not hinder us from achieving the full potential of what we, as human beings, ought to be.
 Spiritual science views man as a fourfold being:
1. The physical-mineral body man has in common with the mineral kingdom.
2. The etheric or life body is the carrier of all life and growth forces. It is the element man has in common with the plant kingdom. Plants have physical and etheric bodies.
3. The astral body is the carrier of feelings, instincts, etc., that man has in common with the animals, which possess a physical, etheric, and astral body.
4. The I, unique spark of divinity in man. It makes possible self-awareness and enables man to become a free being capable of choice between good and evil.— Translator
Thanks to The Rudolf Steiner Archive