This Epistle was written when Symmachus sent his memorial to Valentinian II. St. Ambrose presses on the Emperor the consideration that it is his business to defend religion, and not superstition. The memorial was sent without the adhesion of the Christian senators, and therefore did not represent that body. He warns Valentinian that if he accedes to the request he will incur the censures of the Church, besides acting in a manner derogatory to the memory of his father and brother.