The Ecclesiastical History of Theodoret 77Of the expedition against the Persians.

No sooner had the Persians heard of the death of Constantius, than they took heart, proclaimed war, and marched over the frontier of the Roman empire. Julian therefore determined to muster his forces, though they were a host without a God to guard them. First he sent to Delphi, to Delos and to Dodona, and to the other oracles and enquired of the seers if he should march. They bade him march and promised him victory. One of these oracles I subjoin in proof of their falsehood. It was as follows. "Now we gods all started to get trophies of victory by the river beast and of them I Ares, bold raiser of the din of war, will be leader." Let them that style the Pythian a God wise in word and prince of the muses ridicule the absurdity of the utterance. I who have found out its falsehood will rather pity him who was cheated by it. The oracle called the Tigris "beast" because the river and the animal bear the same name. Rising in the mountains of Armenia, and flowing through Assyria it discharges itself into the Persian gulf. Beguiled by these oracles the unhappy man indulged in dreams of victory, and after fighting with the Persians had visions of a campaign against the Galileans, for so he called the Christians, thinking thus to bring discredit on them. But, man of education as he was, he ought to have bethought him that no mischief is done to reputation by change of name, for even had Socrates been called Critias and Pythagoras Phalaris they would have incurred no disgrace from the change of name--nor yet would Nireus if he had been named Thersites have lost the comeliness with which nature had gifted him. Julian had learned about these things, but laid none of them to heart, and supposed that he could wrong us by using an inappropriate title. He believed the lies of the oracles and threatened to set up in our churches the statue of the goddess of lust.