F. B. Tarbell, A History of Greek Art
“ A serpent, attendant of Athena, strikes its fangs into the giant's right breast. In front of Athena, the Earth-goddess, mother of the giants, half emerging from the ground, pleads for mercy. Above, Victory wings her way to the scene to place a crown upon Athena's head.If we compare the Pergamene altar-frieze with scenes of combat from the best period of Greek art, say with the metopes of the Parthenon or the best preserved frieze of the Mausoleum, we see how much more complicated and confused in composition and how much more violent in spirit is this later work. ”
