 Geisel once called the fish " my version of Cotton Mather " , the Puritan moralist who advised the prosecutors during the Salem witch trials . Betty Mensch and Alan Freeman support this view , writing , " Drawing on old Christian symbolism ( the fish was an ancient sign of Christianity ) Dr. Seuss portrays the fish as a kind of ever @-@ nagging superego , the embodiment of utterly conventionalized morality . " Philip Nel notes that other critics have also compared the fish to the superego . Anna Quindlen called the Cat " pure id " and marked the children , as mediators between the Cat and the fish , as the ego . Mensch and Freeman , however , argue that the Cat shows elements of both id and ego . 
