[4] Two great authorities, divided by more than three centuries, Leon Battista Alberti and Reynolds, have recommended this subdued treatment of white. "It is to be remembered," says the first, "that no surface should be made so white that it cannot be made more so. In white dresses again, it is necessary to stop far short of the last degree of whiteness."--_Della Pittura_, I. ii., compare with Reynolds, vol. i. dis. 8. [5] Vasari observes, "L'unione nella pittura è una discordanza dicolori diversi accordati insième."--Vol. i. c. 18. This observation is repeated by various writers on art in nearly the same words, and at last appears in Sandrart: "Concordia, potissimum picturæ decus, in discordiâ consistit, et quasi litigio colorum."--P. i. c. 5. The source, perhaps, is Aristotle: he observes, "We are delighted with harmony, because it is the union of contrary principles having a ratio to each other."--_Problem._ [6] See "Occolti Trattato de' Colori." Parma, 1568. [7] "Volendo l'uomo accoppiare insième colori che all'occhio dilettino--porrà insième il berrettino col leonato; il verde-giallo con l'incarnato e rosso; il turchino con l'arangi; il morello col verde oscuro; il nero col bianco; il bianco con l'incarnato."--_Dialogo di M. Lodovico Dolce nel quale si ragiona della qualità, diversità, e proprietà de' colori_. Venezia, 1565. NOTE D.--Par. 66. In some of these cases there can be no doubt that Goethe attributes the contrast too exclusively to the physiological cause, without making sufficient allowance for the actual difference in the colour of the lights. The purely physical nature of some coloured shadows was pointed out by Pohlmann; and Dr. Eckermann took some pains to convince Goethe of the necessity of making such a distinction. Goethe at first adhered to his extreme view, but some time afterwards confessed to Dr. Eckermann, that in the case of the blue shadows of snow (74), the reflection of the sky was undoubtedly to be taken into the account. "Both causes may, however, operate together," he observed, "and the contrast which a warm yellow light demands may heighten the effect of the blue." This was all his opponent contended.[1]