Goethe’s Zur Farbenlehre, Theory of Colors, appeared on 16 May 1810. One part of it is a polemic against Newton’s theory of color. Between 1810 and 1832 many natural scientists and mathematicians commented on the work. Almost half of them opposed Goethe. Among the statements from natural science, a third supported him. Hermann von Helmholtz admired Goethe’s scientific work, but he called its main thesis simply wrong. Goethe himself valued his research on color more than all his literary work. He told Johann Peter Eckermann: Auf alles, was ich als Poet geleistet habe, bilde ich mir gar nichts ein. (I think nothing of all that I have achieved as a poet.) What made him proud, he said, was that he was the only one in his century who knew the truth in the difficult science of color.