None of the Greek masterpieces of painting are extant. Their attenuated influence, however, may be traced in the Italian wall paintings from Pompeii and elsewhere. Painting permits greater literalness than sculpture. The picture from Herculaneum, for instance,--Io, Argus, and Mercury (Fig. 47),--tells a definite story and one which is also told by the poets. But the painter has considered the making of a pleasing picture first, and given only a secondary thought to accuracy of tradition. This must be so; for while we may without displeasure listen to the description of a monster, we cannot see his actual representation without discomfort. When we hear how the companions of Ulysses were turned into swine, the tragic note is never lost. To paint this scene, however, and not to border on the ridiculous or the burlesque is given only to the greatest artist--if it is at all possible. Fortunately for our purposes of illustration, there was a class of secondary artists in Greece which did not always shrink from selecting subjects ill adapted for art, and from rendering them with slight variations so that they are neither bad to look at nor altogether untrue. These were the painters of vases. Some of them were masters of their craft (cf. Fig. 116), others were of only mediocre skill. All, however, like their nobler brethren, were primarily concerned with the decorative and technical side of their art and but secondarily with their subject. If the story, for instance, called for four persons and their space for five, they unhesitatingly added the fifth person, and, vice versa, removed one without compunction if they had place for fewer figures than the story demanded. Being, moreover, commercial people, they painted according to fashion. Whatever version of a myth happened to be popular, that they selected, so that it has been possible to trace by their vases the changes which several myths underwent from the sixth century onward. A careful student notices the similarity of types in many of these pictures and realizes that the ancient painter of vases started out with a certain stock-in-trade which he altered as little as possible, adding something new only where it was absolutely necessary. From these observations it is clear that the works of men who were least gifted artistically are the best adapted for the purposes of book illustrations; for a painter is literal in the inverse ratio of his worth as artist. Nothing, therefore, could be less fair than to judge Greek vase painting by the collection of pictures here offered. Only paintings like Figures 85 and 101, for instance, can give a hint of the best that these men produced.