The purpose of sifting the works of a master is to decide upon such as may be considered to be wholly his own, and therefore as material for defining his quality. Not having properly sifted his materials, Dr. Ulmann, as we have seen, has utterly failed to perceive Botticelli's quality; and not having noted that this painter was a linealist who for a decade struggled to become a naturalist only to fall back, under the impulse of Leonardo, to linealism, having failed to describe the orbit of the artist, the author has been unable to make a chronological distribution of his works. Now, without chronological distribution, an artist's works can give us only his quality, and not what we are interested in still more, the evolution of his quality -- that is to say, his character. Dr. Ulmann has failed to reconstruct Botticelli's character and artistic personality, as he has failed to define his quality; and what other ultimate purpose art studies may have than definition of quality and reconstruction of artistic personality, we do not know.