Equipped with a general knowledge of religious antiquity, nobody is surprised by the notion that deities can appear in the shape of animals. Zeus changed himself into a bull to abduct Europe, transformed into a white swan to approach Leda, and assumed the form of an eagle to seduce Ganymede. The Egyptian Thoth most often appeared as an ibis but occasionally transformed himself into a baboon. The ability of many Greek, Roman, Egyptian, and Mesopotamian deities to assume the shape of animals is well known and taken for granted.

Such ideas, however, are not readily associated with early Christian religion. The second-century apologists, for example, vehemently attacked the Greeks' inferior concepts of metamorphosis: