The function of the light-ether, the second of the four modes of ether, can best be envisaged by thinking of the difference between a plant growing in darkness (perhaps a potato sprouting in a cellar) and another of the same species exposed to the influence of the light. On Plates VII and VIII two kinds of unicellular organisms are shown, of one which - the green algae - is accustomed to live in light, the other - the bacilli - in darkness. These things are, of course, well-known facts. Our purpose here, however, is not merely to record them as 'fact', but, by re-creating them within ourselves, to use them to gain an experience of the function of the light-ether.

What we observe here in the sphere of physical light-activity is exactly what the light-ether performs on a higher level of nature when with its help the spiritual archetype of a plant takes on spatial appearance. For to this end the archetype, itself without spatial limitations, imprints its image into the tiny seed, whence the growing plant organism carries it again into space. And there is in principle no limitation to the number of such seeds, each of which will bear the complete image of the archetype.

Scientific thinking, if guided by knowledge of the existence of etheric forces and their action, has no need of such an interpretation of the numerical relationships revealed in the physical world; for it knows them to be nothing but the last expression of the action of the chemical ether (hence occasionally also called 'number-ether' by Rudolf Steiner). To do justice to the appearance of measurable numerical relationships in nature, in whatever sphere, it is necessary to free ourselves from the abstract conception of number which governs modern scientific thought and to replace it by a more concrete one. We shall rind that for the existence of a certain number there may be two quite different reasons, although the method of establishing the number itself is the same in each case. A simple example will illustrate this.

Thus Levity presents itself to us as being engaged in the fourfold activity of Chaoticizing, Weaving, Sounding and, lastly, Speaking the form-creative Cosmic Word into the realm of Gravity.

In the last part of these studies a vista opened up of an inner differentiation of levity itself into warmth, light, chemical action and the formative activity of life. Our next task will be to develop a clearer conception of these four modes of action of levity.

'Tis not the Object, but the Light
That maketh Hev'n. ...'

The following passages from Goethe's Metamorphosis of Plants are a classical example of observation of the activity of the light-ether in the plant. They are taken from the second part of the essay, where Goethe is describing leaf-development:

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Let us look at a number of similar objects, say a group of five apples. We observe that the relation of the number five to the group of objects in front of us is purely external and accidental. In applying to it the conception 'five' we combine the single objects into a group and give it a name, or numerical label, which has nothing to do with the nature of the items making up the group. This way of thinking, we may observe, is of exactly the kind which the nominalists of the Middle Ages attributed to every conception formed by the human mind. In fact, the process of counting is a process of pure abstraction. The more differentiated are the things which we want to combine into a group through the process of counting, the further this abstraction has to go. We can count apples and pears together under the collective conception of 'fruit'; if turnips are added, we must help ourselves out with the conception 'vegetable products'; until finally we deal only with 'things', without considering any qualitative differentiation. Thus the conception of number is created solely within the human mind, which applies it to things from outside.

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