From Emerson's Essays, by Ralph Waldo Emerson
Thus in our fine arts, not imitation but creation is the aim. In landscapes the painter should give the suggestion of a fairer creation than we know. ... he will come to value the expression of nature and not nature itself, and so exalt in his copy the features that please him. He will give the gloom of gloom and the sunshine of sunshine. In a portrait he must inscribe the character and not the features, and must esteem the man who sits to him as himself only an imperfect picture or likeness of the aspiring original within. -- Ralph Waldo Emerson, "Art", p. 184