Apart from the fact that our own way of combining observation and thought guards us against drawing theoretical conclusions from Zeeman's discovery, Rudolf Steiner's indication opens up the prospect of achieving quite practical results, opposite in character to those of the Zeeman effect. For in contradistinction to the use of a magnetic field for splitting the spectrum, Rudolf Steiner has made us aware of the possibility of uniting into a higher synthesis parts of the spectrum which normally appear in separated form. His indication points to nothing less than a leading over of the optically produced spectrum from its usual linear form, with two boundaries on either side, into a closed circular form, and of doing this by an adequate application - as yet undiscovered - of magnetic force. Further, according to his statement, the point where the two ends of the spectrum meet will prove to be a fountain-head of certain higher natural forces which otherwise are not directly accessible.
In order to understand how this is possible, we must remember that in two respects the spectrum is not a complete phenomenon. There is, to begin with, the fact that the colour-band visible on the observation screen is only apparently confined to the surface of the screen. For, as we have seen, because of the differing co-ordination of levity and gravity at the two ends of the spectrum, the conditions of space prevailing at each are polarically opposite. Negative space opens up spherically behind the blue-violet colours on one side, while positive space, filled by the radially shining yellow-red colours, arises on the other. So we see that what we found earlier for the two poles of magnetism and electricity holds good also for the spectrum. That is, the two processes bringing about the relevant phenomena are not confined to the part of space which these phenomena seem to occupy; for the whole positive and negative realms of the universe share in them. Hence the spectrum, though apparently bounded at its two ends, proves by its very nature to be part of a greater whole.
Once before we were led to recognize - though from a different aspect - that the spectrum is a phenomenon which, when rightly viewed, calls for a certain completion. In following Goethe's initial observations we realized that the known spectrum, extending from red via green to violet, has a counterpart extending from violet via peach-blossom to red. The reader may have wondered why we never returned to this other spectrum, in spite of the role it played in making Goethe aware of Newton's error. The reason was that in order to gain the understanding we needed of the spectrum, we had to observe the two border-phenomena independently - that is, without regard to their relative positions. Moreover, with ordinary optical means it is possible to produce only one type of spectrum at a time, so that each is left in need of being complemented by the other. In order to have both together in finite space, as part of one and the same phenomenon, space itself must be dynamically transformed in such a way that the continuation of the finite spectral band running through infinity enters into the finite as well.
Our understanding of magnetism as a specific representation of the polarity of the second order enables us to comprehend, at least in principle, how magnetism might influence - not light itself, as present-day physics erroneously believes - but the secondary polarity of the spectral colours formed out of the primary polarity Light and Dark. To see this in all necessary detail is a task of the future, beyond the scope of this book. We have here to continue our account of Rudolf Steiner's statement by communicating what he indicated concerning the particular nature of the new source of force which would appear in the normally infinite part of the spectrum, if this were brought into the region of the finite.
In order to understand the significance of this indication we must turn our attention to parts of the ordinary spectrum, well known in themselves, which we have purposely left out of our study so far. These are the regions of the ultra-violet and the infra-red, invisible in themselves, but forming part of the spectrum as a whole. The ultraviolet manifests through chemical effects, the infra-red through thermal effects. We have left them out of our considerations because these regions of the spectrum differ from the visible part not only quantitatively, as present-day science believes, but qualitatively also, and in a fundamental way. We must regard them as dynamic realms of particularly extreme spherical and radial activities. As such they represent metamorphoses, in the Goethean sense, of the levity-gravity interaction represented by the optically visible part of the spectrum. In this way the spectrum discloses a threefold differentiation of that region of force, which up to now we have called simply levity, into activities producing chemical, optical and thermal effects.
So far physical investigation is able to lead us, but no further. If, however, we let nature herself speak to us, while holding this differentiated concept of levity in mind, she tells us that beyond the three metamorphoses envisaged so far, there must be a fourth.
Let us remember that it was certain phenomena of life which first made us aware of the existence of a realm of forces with the attributes of anti-gravity, and that these forces revealed themselves first as creators of form. Now it is obvious that warmth, light and chemical energy, though they all play an essential part in living organisms, could never by themselves bring about that 'catching from chaos, carbon, water, lime and what not and fastening them into a given form' which Ruskin describes as the activity of the spirit in the plant. In order to be in this sense an instrument of the spirit active in nature, levity must be capable of yet another metamorphosis into an activity which controls the other three, so that through their action, definitely shaped organic structures may come into being.
The reason why this fourth and highest metamorphosis of Light does not appear in the ordinary spectrum is because it is of too spiritual a quality to be caught by the optical apparatus. In nature herself a creative life-process requires always the presence of a germ already imbued with life. And so, in order to call this fourth metamorphosis of Light into the spectrum, stronger means are needed than the mere optical transformation of light-filled spaces. This stronger agent, according to Rudolf Steiner, is magnetism. With the aid of this it will be possible to organize together round a common spatial centre that part of the activity of levity which escapes the optical instrument and thus remains cosmic, and that part which appears by itself in terrestrial space.
Once this is practically carried out, we may expect a complete colour-circle to appear as already divined by Goethe. The full circle consists of twelve discernible colours, with the Goethean peach-blossom diametrically opposite the green. It is in this region of the peach-blossom that - again according to Rudolf Steiner - we shall find a source of actively working life-forces, springing from the fourth metamorphosis of levity. Such is the prospect for research work guided on the new lines.
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