3. J. B. =Bossuet=, who died in A.D. 1704, Bishop of Meaux, used all his eloquence to prepare a way for the return of Protestants to the church in which alone is salvation. In several treatises he gave an idealized exposition of the Catholic doctrine, glossed over what was most offensive to Protestants, and sought by subtlety and sophistry to represent the Protestant system as contradictory and untenable.[451] During the same period the Spaniard =Spinola=, Bishop of Neustadt, who had come into the country as father confessor of the empress, proposed a scheme of union at the imperial court. The controverted points were to be decided at a free council, but the primacy of the pope and the hierarchical system, as founded _jure humano_, were to be retained. In prosecuting his scheme, with the secret support of Leopold I., Spinola, between A.D. 1676 and 1691, travelled through all Protestant Germany. He found most success, out of respect for the emperor, in Hanover, where the Abbot of Loccum, Molanus, zealously advocated the proposed union, in which on the Catholic side Bossuet, on the Protestant side the great philosopher =Leibnitz=, took part. But the negotiations ended in no practical result. That Leibnitz had himself been already secretly inclined to Catholicism, some think to have proved by a manuscript, found after his death, entitled in another’s hand, “_Systema Theologicum Leibnitii_.” Favourably disposed as Leibnitz was to investigate and recognise what was profound and true even in Catholicism, so that he reached the conviction that neither of the two churches had given perfect and adequate expression to Christian truth, he has apparently sought in this work to make clear to himself what and how much of specifically Catholic doctrines were justifiable, and to sketch out a system of doctrine occupying a place superior to both confessions. In this treatise many doctrines are expressed in a manner quite divergent from that of the Tridentine creed, while several expressions show how clearly he perceived the contradiction between his own Protestant faith and the Romish system, amid all his attempts to effect a reconciliation.