Not long after the accession of Valens, Basil was ordained presbyter by Eusebius. An earlier date has been suggested, but the year 364 is accepted as fitting in better with the words of Gregory on the free speech conceded to heretics. And from the same Letter it may be concluded that the ordination of Basil, like that of Gregory himself, was not wholly voluntary, and that he was forced against his inclinations to accept duties when he hesitated as to his liking and fitness for them. It was about this time that he wrote his Books against Eunomius; and it may possibly have been this work which specially commended him to Eusebius. However this may be, there is no doubt that he was soon actively engaged in the practical work of the diocese, and made himself very useful to Eusebius. But Basil's very vigour and value seem to have been the cause of some alienation between him and his bishop. His friend Gregory gives us no details, but it may be inferred from what he says that he thought Basil ill-used. And allusions of Basil have been supposed to imply his own sense of discourtesy and neglect. The position became serious. Bishops who had objected to the tumultuary nomination of Eusebius, and had with difficulty been induced to maintain the lawfulness of his consecration, were ready to consecrate Basil in his place. But Basil shewed at once his wisdom and his magnanimity. A division of the orthodox clergy of Cappadocia would be full of danger to the cause. He would accept no personal advancement to the damage of the Church. He retired with his friend Gregory to his Pontic monasteries, and won the battle by flying from the field. Eusebius was left unmolested, and the character of Basil was higher than ever.
The seclusion of Basil in Pontus seemed to afford an opportunity to his opponents in Cappadocia, and according to Sozomen, Valens himself, in 365, was moved to threaten Cæsarea with a visit by the thought that the Catholics of Cappadocia were now deprived of the aid of their strongest champion. Eusebius would have invoked Gregory, and left Basil alone. Gregory, however, refused to act without his friend, and, with much tact and good feeling, succeeded in atoning the two offended parties. Eusebius at first resented Gregory's earnest advocacy of his absent friend, and was inclined to resent what seemed the somewhat impertinent interference of a junior. But Gregory happily appealed to the archbishop's sense of justice and superiority to the common unwillingness of high dignitaries to accept counsel, and assured him that in all that he had written on the subject he had meant to avoid all possible offence, and to keep within the bounds of spiritual and philosophic discipline. Basil returned to the metropolitan city, ready to cooperate loyally with Eusebius, and to employ all his eloquence and learning against the proposed Arian aggression. To the grateful Catholics it seemed as though the mere knowledge that Basil was in Cæsarea was enough to turn Valens with his bishops to flight, and the tidings, brought by a furious rider, of the revolt of Procopius, seemed a comparatively insignificant motive for the emperor's departure.
There was now a lull in the storm. Basil, completely reconciled to Eusebius, began to consolidate the archiepiscopal power which he afterward wielded as his own, over the various provinces in which the metropolitan of Cæsarea exercised exarchic authority. In the meantime the Semiarians were beginning to share with the Catholics the hardships inflicted by the imperial power. At Lampsacus in 364 they had condemned the results of Ariminum and Constantinople, and had reasserted the Antiochene Dedication Creed of 341. In 366 they sent deputies to Liberius at Rome, who proved their orthodoxy by subscribing the Nicene Creed. Basil had not been present at Lampsacus, but he had met Eustathius and other bishops on their way thither, and had no doubt influenced the decisions of the synod. Now the deputation to the West consisted of three of those bishops with whom he was in communication, Eustathius of Sebasteia, Silvanus of Tarsus, and Theophilus of Castabala. To the first it was an opportunity for regaining a position among the orthodox prelates. It can hardly have been without the persuasion of Basil that the deputation went so far as they did in accepting the homoousion, but it is a little singular, and indicative of the comparatively slow awakening of the Church in general to the perils of the degradation of the Holy Ghost, that no profession of faith was demanded from the Lampsacene delegates on this subject. In 367 the council of Tyana accepted the restitution of the Semiarian bishops, and so far peace had been promoted. To this period may very probably be referred the compilation of the Liturgy which formed the basis of that which bears Basil's name. The claims of theology and of ecclesiastical administration in Basil's time did not, however, prevent him from devoting much of his vast energy to works of charity. Probably the great hospital for the housing and relief of travellers and the poor, which he established in the suburbs of Cæsarea, was planned, if not begun, in the latter years of his presbyterate, for its size and importance were made pretexts for denouncing him to Elias, the governor of Cappadocia, in 372, and at the same period Valens contributed to its endowment. It was so extensive as to go by the name of Newtown, and was in later years known as the |Basileiad.| It was the mother of other similar institutions in the country-districts of the province, each under a Chorepiscopus. But whether the Ptochotrophium was or was not actually begun before Basil's episcopate, great demands were made on his sympathy and energy by the great drought and consequent famine which befell Cæsarea in 368. He describes it with eloquence in his Homily On the Famine and Drought. The distress was cruel and widespread. The distance of Cæsarea from the coast increased the difficulty of supplying provisions. Speculators, scratching, as it were, in their country's wounds, hoarded grain in the hope of selling at famine prices. These Basil moved to open their stores. He distributed lavishly at his own expense, and ministered in person to the wants of the sufferers. Gregory of Nazianzus gives us a picture of his illustrious friend standing in the midst of a great crowd of men and women and children, some scarcely able to breathe; of servants bringing in piles of such food as is best suited to the weak state of the famishing sufferers; of Basil with his own hands distributing nourishment, and with his own voice cheering and encouraging the sufferers.
About this time Basil suffered a great loss in the death of his mother, and sought solace in a visit to his friend Eusebius at Samosata. But the cheering effect of his journey was lessened by the news, which greeted him on his return, that the Arians had succeeded in placing one of their number in the see of Tarsus. The loss of Silvanus was ere long followed by a death of yet graver moment to the Church. In the middle of 370 died Eusebius, breathing his last in the arms of Basil.