Rudolf Steiner, from a lecture given in Dornach July 31, 1915:
Every thought is essentially different from what people usually believe it to be. People take it to be a reproduction of something perceptible. It is not recognized as a form builder, a molder. Every thought that arises in us seizes, as it were, upon our inner life and shares (at first as we are growing) in our whole human construction. It already takes part in building our structure before we are born and belongs to the forming forces of our nature. It goes on working continually and again and again replaces what dies away in us. So it is not only the case that we perceive our concepts externally, but that we are always working upon our being through our thoughts; through what we picture mentally, we are working continuously to shape and build ourselves anew.
Seen with the eyes of spiritual science, every thought appears like a head with a sort of continuation downwards, so that with every thought we actually insert into us somehting like a shadowy outline, a phantom, of ourselves; not exactly like us, but as similar as a shadow picture. This phantom of ourselves must be inserted, for we are continually losing something; something is being destroyed, is crumbling away. And what the thought inserts into our human form preserves us, generally speaking, until our death. Thought is thus at the same time a definite inner activity, a working on our own construction.
The Western worldview has practically no knowledge of this at all. People do not sense or feel inwardly how the thought grips them, how it really spreads itself out in them. Now and again a person will feel in breathing—though for the most part it is no longer noticed—that the breath spreads out in him, and that breathing has something to do with his rebuilding and regeneration. This applies also to thoughts, but the European scarcely feels any longer that the thought is striving all the time to become man, or better said, to form the human shape.
But unless we arrive at a feeling of such forces within us, we can hardly reach a right understanding, based on inner feeling and life, of what spiritual science really desires. For spiritual science is not active at all in what thought yields us inasmuch it reproduces something external; it works in the life element of thought, in this continuous shaping process of the thought.
Therefore it has been very difficult for many centuries to speak of spiritual science or to be understood when it was spoken of, because the awareness just characterized became increasingly lost to European humanity. In the Eastern worldview this feeling about thought which I have just expressed exists to high degree. At least the consciousness exists to a high degree that one must seek for this feeling of an inner experience of thought. The inclination of the Eastern person for meditation comes from this. For meditation should be a familiarizing of oneself with the shaping forces of thought, a becoming aware of the living feeling of the thought. That the thought accomplishes something in us should become known to us during meditation. Therefore we find in the East such expressions as: A becoming one, in meditation, with Brahma, with the fashioning process of the world. What is sought in the Eastern worldview is the consciousness that when one lives rightly into the thought, one not only has somehting in oneself, not only thinks, but one becomes at home in the fashioning forces of the world. But it is rigidified, because the Eastern worldview has neglected to acquire an understanding for the Mystery of Golgotha.
To be sure, the Eastern worldview—of which we have yet to speak—is eminently fitted to become at home in the forming forces of thought life, but nevertheless in so doing, it comes into a dying element, into a web of abstract, dead mental pictures. So that one could say: whereas the right way is to experience the life of the thought world, the Eastern worldview feels at home in a reflection of the life of thought. One should become at home in the thought world as if one were transposing oneself into a living being; but there is a differnce between a living being and a reproduction of a living being, let us say a papier-mache copy. The Eastern worldview—whether Brahmanism, Buddhism, or the Chinese and Japanese religions—does not become at home in the living being but in something that may be described as a copy of the thought world, which is related to the living thought world as the papier-mache organism is related to the living organism.
This, then, is the difficulty....
Source: The Tree of Life and the Tree of Knowledge, Mercury Press, pp. 30-31