Goethe's Theory of Colours · Johann Wolfgang von Goethe
217.
In all this we are never to forget that this appearance is not to be considered as a complete or final state, but always as a progressive, increasing, and, in many senses, controllable appearance. Thus we find that, by the negation of the above five conditions, it gradually decreases, and at last disappears altogether. [1] Plate 2, fig. 5, _left_. [2] Plate 2, fig. 5, _right_. [3] This pure red, the union of orange and violet, is considered by the author the maximum of the coloured appearance: he has appropriated the term _purpur_ to it. See paragraph 703, and _note_.--T. [4] The bands or stripes in fig. 4, plate 1, when viewed through a prism, exhibit the colours represented in plate 2, fig. 5. Before we proceed further, it is incumbent on us to explain the first tolerably simple phenomenon, and to show its connexion with the principles first laid down, in order that the observer of nature may be enabled clearly to comprehend the more complicated appearances that follow. In the first place, it is necessary to remember that we have to do with circumscribed objects. In the act of seeing, generally, it is the circumscribed visible which chiefly invites our observation; and in the present instance, in speaking of the appearance of colour, as occasioned by refraction, the circumscribed visible, the detached object solely occupies our attention.
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