But Ambrose had powerful enemies to contend with in his defence of the received doctrines of the Church.  The Empress Faustina was herself an Arian, and the patroness of the sect.  Milan was filled with its defenders, turbulent and insolent under the shield of the court.  It was the headquarters of the sect at that time.  Arianism was fashionable; and the empress had caused an edict to be passed, in the name of her son Valentinian, by which liberty of conscience and worship was granted to the Arians.  She also caused a bishop of her nomination and creed to challenge Ambrose to a public disputation in her palace on the points in question.  Now what course did Ambrose pursue?  Nothing could be fairer, apparently, than the proposal of the empress,—­nothing more just than her demands.  We should say that she had enlightened reason on her side, for heresy can never be exterminated by force, unless the force is overwhelming,—­as in the persecution of the Huguenots by Louis XIV., or the slaughter of the Albigenses by Innocent III. or the princes he incited to that cruel act.  Ambrose, however, did not regard the edict as suggested by the love of toleration, but as the desire for ascendency,—­as an advanced post to be taken in the conflict,—­introductory to the triumph of the Arian doctrines in the West, and which the Arian emperor and his bishops intended should ultimately be the established religion of the Western nations.  It was not a fight for toleration, but for ascendency.  Moreover Ambrose saw in Arianism a hostile creed,—­a dangerous error, subversive of what is most vital in Christianity.  So he determined to make no concessions at all, to give no foothold to the enemy in a desperate fight.  The least concession, he thought, would be followed by the demand for new concessions, and would be a cause of rejoicing to his enemies and of humiliation to his friends; and in accordance with the everlasting principles of all successful warfare he resolved to yield not one jot or tittle.  The slightest concession was a compromise, and a compromise might lead to defeat.  There could be no compromise on such a vital question as the divinity of our Lord.  He might have conceded the wisdom of compromise in some quarrel about temporal matters.  Had he, as governor of a province, been required to make some concession to conquering barbarians,—­had he been a modern statesman devising a constitution, a matter of government,—­he might have acted differently.  A policy about tariffs and revenues, all resting on unsettled principles of political economy, may have been a matter of compromise,—­not the fundamental principles of the Christian religion, as declared by inspiration, and which he was bound to accept as they were revealed and declared, whether they could be reconciled with his reason or not.  There is great moral grandeur in the conflict of fundamental principles of religion; and there is equal grandeur in the conflict between principles and principalities, between combatants armed with spiritual weapons and combatants armed with the temporal sword, between defenceless priests and powerful emperors, between subjects and the powers that be, between men speaking in the name of God Almighty and men at the head of armies,—­the former strong in the invisible power of truth; the latter resplendent with material forces.