The two outer limits, matter and consciousness, at which ordinary natural science halts and a trained, Goethean knowing has to take over.
The boundaries of natural science, in Rudolf Steiner's reading, are two. Toward one limit lies matter, which physics presupposes everywhere yet can never lay its hands on. Toward the other lies consciousness, which clearly exists yet cannot be derived from any material process. Science works brilliantly between these poles and stalls at both. Steiner named the stalling not a defeat but a doorway.
The Boundaries of Natural Science in Anthroposophy is Rudolf Steiner's account of the two outer limits at which ordinary natural science halts: matter, which the senses assume yet never locate, and consciousness, which arises within the sensory world though no one can explain how. Set out in his 1920 Dornach lecture course of the same name, GA 322, the idea answers du Bois-Reymond's 1872 verdict of Ignorabimus, we shall not know. Steiner places these boundaries at the poles of human experience, the realm where Karl Marx fixed everything in matter and Max Stirner dissolved everything into the ego. Rather than treating the limit as a wall, he reads it as the threshold where a trained, Goethean way of knowing must begin. Today it underwrites anthroposophical epistemology and the participatory science worked at the Goetheanum.
In Steiner's Own Words
While Karl Marx occupies one of the two poles of human experience mentioned yesterday, the pole of matter upon which he bares all his considerations, Stirner, the philosopher of the ego, proceeds from the opposite pole, that of consciousness. And just as the modern world view, gravitating toward the pole of matter, becomes unable to discover consciousness within that element (as we saw yesterday in the example of du Bois-Reymond), a person who gravitates to the opposite pole of consciousness will not be able to find the material world.
What it Means Today
Read as epistemology, the GA 322 course makes a precise claim about where knowing breaks down. Steiner's argument is that the same clear concepts that win us the sense world fail at its edges: push them past the senses and they manufacture atoms and force-fields that the mind has merely rolled on into out of habit; turn them inward on consciousness, and they cannot reach it at all. The 1872 Ignorabimus of Emil du Bois-Reymond, we shall not know, is for Steiner not a stopping point but a symptom, a sign that ordinary cognition has met its proper frontier.
One contemporary thinker carried this further than most. Owen Barfield, in Saving the Appearances: A Study in Idolatry (Faber, 1957), argued that modern science treats its own models, the particles behind the colours, as if they were the world itself, and forgets the participating mind that helped constitute them. That is exactly the inert rolling-on Steiner warned against. Barfield's correction, like Steiner's, is not to abandon science but to add a second faculty to it. Steiner's own remedy was a discipline of cognition he called Imagination, an exact attention that stays inside the phenomena rather than guessing behind them. The lineage is institutional, not merely literary: the Natural Science Section at the Goetheanum in Dornach, founded in 1924, still pursues this participatory study of light, plant, and colour, treating Steiner's two boundaries less as the end of knowledge than as the place where a different kind of knowing has to be learned.
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