The criticism was made, when the first edition of this work was published, that it was illustrated with "details" taken from the works of the masters rather than with the works themselves. This criticism would be justified—each work forming an ensemble from which, in principle, nothing should be cut away—if, in the case of certain pictures, the reduction to the size of a page did not deprive the character of the work of its whole appeal to the senses. Have not books been published wherein the "Marriage at Cana" was reduced to the size of the half of a visiting card? And besides, is it not already admitted that one may detach a statue from the porch of a cathedral in order to illustrate a book with it, and that the reproduction of the apse of that cathedral may give a more correct idea of its character than an illustration, too greatly reduced in size, of the cathedral itself? There is no question, in such a book as I have intended this to be, of describing the pictures by the masters under consideration; the problem is one of expressing the spirit of the ensemble of their work. I do not comment upon the picture through the text; I justify the text through the picture or through a fragment of the picture.