Goethe's Theory of Colours · Johann Wolfgang von Goethe
449.
The glasses employed for the experiments are to be regarded as the utmost possible practical approach to transparence. By the intimate contact, however, occasioned by the pressure applied to them, their surfaces, we are persuaded, immediately become in a very slight degree dimmed. Within this semi-transparence the colours immediately appear, and every circle comprehends the whole scale; for when the two opposites, yellow and blue, are united by their red extremities, pure red appears: the green, on the other hand, as in prismatic experiments, when yellow and blue touch. We have already repeatedly found that where colour exists at all, the whole scale is soon called into existence; a similar principle may be said to lurk in the nature of every physical phenomenon; it already follows, from the idea of polar opposition, from which an elementary unity or completeness results.
Text from Project Gutenberg, public domain in the United States.