Plutarch devotes one of his two Jewish questions in his Quaestionum Convivalium to the God of the Jews. The discussion is very well informed, depending as it does on Hecataeus of Abdera, and is mainly devoted to Jewish ritual, arguing that its similarities prove the identity of the God of the Jews with Dionysus. Though interpretatio Graeca is a well-known phenomenon, Plutarch’s approach here is quite astonishing. Despite his involvement and deep interest in religion, including foreign (e.g., Egyptian) religions he entirely disregards what is considered by moderns as Judaism’s most prominent feature contrasting it with ‘pagan’ antiquity, monotheism—as he was also totally ignoring the young and rising Christianity. This chapter will try to provide the background to this strange silence.