If one exposes an arrangement like this to the action of the prism, whose position has remained unchanged, colours appear on each of the two edges, as before, but in reverse order (Fig. iii). The spectral phenomenon now begins at one side with light blue and passes into indigo and violet, with uncoloured darkness in the centre. From this darkness it emerges through red and passes through orange to yellow at the other end. Again, where the two interior colour-cones merge, there an additional colour appears. Like green, it is of a neutral character, but at the same time its quality is opposite to that of green. In Newtonian optics, which assumes colour to be derived from light only, this colour has naturally no existence. Yet in an optics which has learnt to reckon with both darkness and light as generators of colour, the complete spectrum phenomenon includes this colour equally with green. For lack of an existing proper name for it, Goethe termed it 'pure red' (since it was free from both the blue tinge of the mauve, and the yellow tinge of the red end of the ordinary spectrum), or 'peach-blossom' (pfirsichblüt), or 'purple' (as being nearest to the dye-stuff so called by the ancients after the mollusc from which it was obtained).10 It needs only a glance through the prism into the sunlit world to make one convinced of the natural appearing of this delicate and at the same time powerfully luminous colour. For a narrow dark object on a light field is a much commoner occurrence in nature than the enclosing by two broad objects of a narrow space of light, the condition necessary for the emergence of a continuous colour-band with green in the middle. In fact, the spectrum which science since the time of Newton regards as the only one, appears much more rarely among natural conditions than does Goethe's counter-spectrum. With the peach-blossom a fresh proof is supplied that what man experiences in his soul is in harmony with the objective facts of nature. As with green, we experience peach-blossom as a colour that leaves us in equilibrium. With peach-blossom, however, the equilibrium is of a different kind, owing to the fact that it arises from the union of the colour-poles, not at their original stage but in their 'heightened' form. And so green, the colour of the plant-world harmony given by nature, stands over against 'purple', the colour of the human being striving towards harmony. By virtue of this quality, purple served from antiquity for the vesture of those who have reached the highest stage of human development for their time. This characteristic of the middle colours of the two spectra was expressed by Goethe when he called green 'real totality', and peach-blossom 'ideal totality'.