The problem of the Unity of Christendom, and in particular of the reconciliation of the East, has occupied the minds of the Popes, sometimes more sometimes less urgently, since the consummation of the schism under Michael Cerularius in the eleventh century. But hitherto all their efforts have been in vain. The Councils of Lyons and Florence were abortive. The personal efforts of individual Popes have not met with any greater success. In the last century Popes Pius IX and Leo XIII both tried to reopen official relations with the East, but their overtures were rejected. Yet, nothing daunted, the Holy See is now embarked upon another effort after Christian Unity.

It would appear that in this new effort the Holy See is approaching the matter, not with any less courage or confidence, not in any spirit of compromise or dissimulation of the truth, but with a special emphasis on what may be called the psychological conditions of the problem. It would have the apostles of unity set forth the Catholic doctrine in its fullness; but it would have them also approach their enterprise in the spirt of charity and sympathy. It would have them endeavour, before all else, to remove prejudice and misunderstanding, to abstain from acute controversy, to create an atmosphere of peace and mutual sympathy.

For what is the main obstacle to Christian Unity? There are, of course, dogmatic obstacles, reducible finally, at least in the case of the Eastern Churches, to the one point of the Primacy of the Apostolic See. But it appears to the Holy Father that dogma is not the whole difficulty, nor the most immediate difficulty.