On May 12, 1922, Rudolf Steiner delivered a lecture in Berlin that so comprehensively explained anthroposophy, it is nearly impossible to summarize. Please read the full lecture linked below. He outlines the problem with spiritualism and mediumship that was the fashion at the time. Anthroposophy approaches the spiritual world with people who are healthy in both soul and body, unlike the medium. Two different paths were historically used for spiritual development: 1) yoga through the breath and respiratory system; and 2) asceticism through suppression and dampening of instincts, drives and passions. Neither of these methods are suitable for Western civilization today. Rather, we must delve deeper, beyond our thinking and feeling, into the human will to remain "in full vigor and fitness for external life."
We can't advance spiritually by avoiding what is unpleasant. Rather, we must be in the world by turning inward or denying that which is outside ourselves. We enliven our thinking by observing the phenomena of the external world, both the beautiful and the ugly. The pain and suffering we then experience from developing the will through spiritual exercises brings personal transformation.
By experiencing reality through suffering, we experience the spiritual world—which we now grasp with living thought—with the same degree of reality with which we experience the sensory world through our senses. Through this, we become a wholly spiritual sense organ, if I may use this paradoxical, self-contradictory, yet very real expression, and only as whole human beings can we become this. Then we perceive the spiritual world in its reality. Then we know how the living thought is just as much a reality as, in ordinary life, we know how to distinguish a piece of hot iron that we actually grasp with our fingers from one that we merely conjure up in our imagination.
Thus, these two things go hand in hand in the perception of the higher, supersensible world: that the living thought is experienced within the human being, and that, through inner, soulful pain, the human being’s entire being is permeated by inner sensitivity. Thought must come alive—the whole human being must become a being of feeling during those moments of life when he seeks a connection to the spiritual world. We see that, as modern people, we remain entirely within the realm of the soul. We do not turn to the process that strengthens consciousness through regulated or irregular breathing. Nor do we turn to the process that slows down our bodily functions. With our exercises, we remain entirely within the realm of the soul, yet on a different level we develop the very same faculties that were cultivated through yoga practice and asceticism for the perception of the higher world. We develop these higher insights and yet remain human beings who can fully face the rigors of life, who need not withdraw into seclusion—neither as people of knowledge nor as people of action. Why is that? We perform only inner soul exercises, yet through them we arrive at the empowered thought—the very thought that was empowered in the Indian yogi solely by allowing the stronger current to flow into the current of breathing. And on the other hand, purely inwardly and spiritually, we arrive at what, in a certain sense, becomes a kind of attunement of the physical processes. But we now have both within our grasp. We have the power, for example, to ensure that suffering remains purely spiritual, and that we can return at any time—when we awaken from sleep—to our healthy state of mind and body. For it must be emphasized again and again that what matters in anthroposophical methods is that we can return from that state which leads us into the spiritual world to the state where we stand with both feet firmly on the earth.
We begin to see other human beings as "agents" of spiritual beings. We come to understand karma, reincarnation and desitiny in the context of human freedom. It is sought through human suffering and growth from those experiences.
This is the anthroposophical path into the spiritual world. And this path also explains why those who do not wish to follow it now condemn it so vehemently, as we see today. They have an unconscious aversion to what must one day be overcome through higher knowledge—to suffering, to that which brings human functions into a certain state of calm, but a calm that is subject to an inner mastery. They therefore prefer to see visions and the like emerge from a subdued physical state—as in the case of a medium—which, however, have no value as knowledge. Whereas true knowledge arises not from experiencing what is brought about by the outer physical body, but from what is experienced from within the soul—albeit as a certain suffering—which guarantees the certainty of the supersensible world.
Rudolf Steiner makes the distinction between "beautiful, grand ideas about the spirit" that lack living spirit and true, enlivened thinking that comes with a strong does of human suffering. Then, we begin to develop "spiritual blood" that courses through us just like physical blood. We become "elivened" with spirit. By doing so, become "companions of spiritual beings who walk among us."
We will relate to the world in an entirely different way, and the great enigmas of the present and the near future will present themselves to us in a completely different light when we cease to merely think of a dead spirit, but when we can once again say: We humans are not alone on Earth; we do not merely carry thoughts of a spirit within us—thoughts that, as mere thoughts, are unproven and lead, on the one hand, to superstition and, on the other, to doubt. For we can say with certainty: We are not alone on Earth; spiritual beings are among us, are connected to us; spiritual beings work with us to shape the course of the world, and we shape the course of the world when we enter into a relationship with them!
Thus, anthroposophy does not seek the spirit, which often proves to be a lifeless presence in life and can offer us only a dim picture of the future. Rather, anthroposophy turns to the living spirit, so that people may not only have ideas about the spirit, but may have the living spirit walking among them!
Read more: Rudolf Steiner, The Essence of Anthroposophy, Lecture 9, GA 80a, 12 May 1922, Berlin.