The Rudolf Steiner Archive

5. Embryology, Sexual Reproduction

[ 1 ] I was asked a legitimate question, which was: When and how does the union of the ego—the true human self—with its various bodies take place?

[ 2 ] In answering this question, I am compelled to go into great detail. For I wish to provide an answer in accordance with the latest findings of modern science, in order to demonstrate the harmony between science and theosophical wisdom.

[ 3 ] The moment when the soul takes up residence in the body—that is the moment I was asked about. Let’s use an analogy to answer this question: the analogy between a house and its inhabitants—that is, between the body and the soul. It’s quite clear, after all, that the inhabitant will adapt the house to suit his or her occupation. However, the house also depends on the foundation upon which it is built. It can also be destroyed by forces that have nothing to do with the inhabitant—such as the weather, for example. The same is true of our body in relation to its soul. The body and the soul are each subject to their own laws. Body and soul relate to one another like a house and its occupant. They coexist only for a time. Form and structure are shaped according to needs—for example, according to one’s profession.

[ 4 ] From the standpoint of theosophy, we cannot consider only the external laws. We must also ask ourselves: How is the house prepared? When does the body become capable of serving as a vessel? How does the soul develop up to the point at which it takes possession of the physical house?

[ 5 ] When we look at theosophical literature today, it provides us with no insight into the states of the soul before birth. However, scientific research into the nature of the physical body and how it is structured has reached an important stage. Physical science is bringing us closer to an understanding of this with each passing day. Yet the findings of science are uncertain in many ways, and they bring a multitude of new insights.

[ 6 ] My answer is based on the current state of scientific knowledge. It is not a matter of dogmatic belief. After all, science must continue to advance day by day.

[ 7 ] Now let us consider the stages of the soul between two incarnations. At first, it is in the Arupa realm within Devachan. Initially, the state of the soul can be compared to that of a plant seed. The entire plant is condensed for a time into the tiny, point-like lily seed. The entire lily is already contained within the seed, though invisible to our physical eyes. The entire plant is already contained [spiritually] within the tiny seed. This can take various forms within the seed. When we look at the seed in this way, however, it is quite different from what the soul was before and will be afterward. But the soul is also in a state where it is completely freed from all veils. It is part of the plan of development that it must feel free and unhindered for a time. Then it can apply the strength it has gained in this freedom to the new incarnation.

[ 8 ] Descending from this highest plane, the soul then surrounds itself with mental substance—the mental body. Then, moving on, it surrounds itself with astral substance. In the period before birth, this is an extremely dynamic process. The Self becomes an extremely mobile organ at this stage. The Self appears there in a funnel-like shape and also with a certain coloration. The central part radiates like the rays of stars. The germ, which comes from the Devachan, is enclosed in a cylinder of light and radiates golden-yellow light; this then surrounds itself with astral substance, so that the Self takes on such a funnel-shaped form. This takes place with tremendous speed. What is contained within the golden-yellow cylinder of rays is the mental-astral sheath of the Self.

[ 9 ] Aristotle provides us with a term for this: “nous poeticos,” the higher power of the soul, and “nous pateticos,” the soul’s perceptions and faculty of perception, once the soul is incarnated in the flesh.

[ 10 ] Such a funnel shape can never be associated with a body whose form does not correspond to it. And yet one funnel may be very large and the other very small, depending on the human embryo. Only now are the latest scientific studies able to shed light on the development of the animal-human organism.

[ 11 ] Such research was conducted in Corsica in 1875. The researchers had made such progress there that they were able to say: Here, at this point, the human personality begins. The materialist researcher might say: We now understand the processes that lead to existence on the material plane. But if we knew nothing about these preceding states, modern natural science would only enable us to study our outer personality.

[ 12 ] At the same time as this new starting point for research emerged, theosophical wisdom about the world was revealed in the same year. The discovery that sheds light on the development of the animal-human organism coincides with the proclamation of wisdom about the human soul by the Theosophical Society. Modern natural science has reached a standpoint not unlike that of Aristotle.

[ 13 ] One might ask: Why did sexuality—gender—emerge at all during the third round? After all, reproduction had previously taken place in an asexual manner. All religions trace their origins back to the human being who was neither male nor female—to Adam Kadmon. Now one might ask: Why does reproduction now take place in a sexual manner? Researchers of the mysteries have always had an answer to this. I want to give you the answer in the language of modern science. It was previously believed that the entire process of fertilization was something other than what has now been revealed. This question has now become the subject of serious scientific investigation. But what do the scientific findings reveal regarding the question of sexual reproduction? Sexual reproduction is, after all, not necessary by nature. Nature could, after all, have managed in a different way. Science therefore no longer asserts that both sexes are equally necessary for reproduction. And this is correct, for the female alone would suffice for mere reproduction. Nevertheless, nature has chosen a different path—namely, the path of the mingling of the sexes—after two sexes were created. And why would it do this if it could achieve the same result without such mingling? Well, nature chose to create two sexes and then to intermingle them because it foresaw that, beginning with the third [root] race, human selves would wish to incarnate, and that sexual reproduction would be necessary for this incarnation.

[ 14 ] This means: Nature also prepared this point in time, from which point onward human intelligence was to reincarnate again and again into shells, into bodies. From this point onward, when human selves wished to incarnate, procreation was to take place through the union of the two sexes. And why was this to happen? So that with each new incarnation, a mixture of qualities—a blend of characteristics—could come into being that had not existed before. Reproduction, therefore, occurred simply because one personality, in union with another, became capable of bringing forth a new one. Previously, there had been an extraordinary resemblance to one’s ancestors. Without the two sexes, humans would indeed undergo a slight change through contact with the outside world, but they would essentially have always remained similar to their ancestors, just as the lily daughter resembles the lily mother.

[ 15 ] As we can see, the child inherits not only the mother’s characteristics but also those of the father. In this hybrid, a completely different kind of new being emerges, and thus the individual human being becomes the result of two entirely different streams. Everything physical and material is provided solely by the mother’s body. And the male sex is there only so that the characteristics can be altered. The male sex thus merely provides the impetus for this. The male penetrates the maternal, and what occurs is not a union, as was once believed, but rather the emergence of a radiating body—called the centrosome. Without this centrosome, reproduction does not occur. In lower animals, reproduction can even be induced by bringing the cells into contact with an acid. Two nuclei then appear. The reappearance of two nuclei looks something like this: one nucleus attracts the male characteristics, the other the female characteristics.

[ 16 ] However, this state is not yet capable of receiving a soul seed; it can only be used to build new cells. This process follows the following pattern: 1, 2, 4, 8, 16 cells, and so on, until the state of a mulberry seed is reached. As an occult researcher, you can perceive, in addition to what I have just described, the force at work here. This force has been passed down from the ancestors. What we call “physical prana” has a rose-colored hue. It permeates the cells during their formation and proliferation. “Physical prana” can carry the process even further. The mulberry embryo is then divided into two layers. Through this process, a soul germ has united with the human germ. When we consider these processes, we have arrived at the first days of embryonic life. The ray cylinder within the funnel disappears. It divides into two stars. These two stars are the formative forces behind what develops within the two layers here. Each of the stars takes hold of one of the two layers. They migrate into the embryo. It is these stars that then form the basis for the two nervous systems: the sympathetic nervous system—the unconscious nervous system that governs vegetative functions—and the central nervous system. Then the “astral prana” is added. The same process also occurs in the germ of a higher animal. In the beginning, the germ of a higher animal cannot be distinguished from the human germ.

[ 17 ] This thickening marks the actual emergence of the segmented spinal cord. On one side, you can see five vesicles forming. From the first [develops] the forebrain, from the second the midbrain, from the third the hindbrain, and finally the hindbrain.

[ 18 ] Now the beam of light, which had disappeared, reappears (between the 20th and 30th days). The prana current has already organized the brain and the spinal cord. From there, it enters the prepared human brain as mental prana. So we have a “physical prana,” then a second prana under the guidance of the astral, which is active in the sympathetic nervous system and builds up the brain so that the true Self can enter the prepared brain. It is not yet present, nor is it yet perceptible externally. Each soul force forms its own organs. Starting from the brain, the dormant Self continues to develop in order to adapt. Then the Self enters the organism as “mental prana.”

[ 19 ] We are dealing with a threefold fertilization. First, on the physical plane; second, a dual fertilization on the astral plane; and third, the infusion of the Self. For this to happen, there must be a single body. And this can only occur—can only be achieved—through the blending of maternal-feminine and [paternal-]masculine qualities, through the duality of the sexes.

[ 20 ] We have thus recognized the true purpose of sexual reproduction. Sexual reproduction should therefore be understood not as a cause, but as an end.

[ 21 ] The next question would be that of the states after death. Furthermore, the question: What happens to our powers of perception after death, after we shed our physical forms?