19. In the treatise, published long after his death, in 1697, De tolerantia Reformatorum circa quæstiones inter ipsos et Augustanam confessionem professes controversas consultatio, it is his object to prove that the Calvinists held no such tenets as should exclude them from Christian communion. He does not deny or extenuate the reality of their differences from the Confession of Augsburg. The Lutherans, though many of them, he says, had formerly maintained the absolute decrees of predestination, were now come round to the doctrine of the first four centuries.[72] And he admits that the Calvinists, whatever phrases they may use, do not believe a true and substantial presence in the Eucharist.[73] But neither of these errors if such they are, he takes to be fundamental. In a shorter and more valuable treatise, entitled Desiderium et studium concordiæ, ecclesiasticæ, Calixtus proposes some excellent rules for allaying religious heats. But he leans far too much towards the authority of tradition. Every church, he says, which affirms what others deny, is bound to prove its affirmation; first by Scripture, in which whatever is contained must be out of controversy, and secondly (as Scripture bears witness to the church that it is the pillar and foundation of truth, and especially the primitive church which is called that of the saints and martyrs), by the unanimous consent of the ancient church; above all, where the debate is among learned men. The agreement of the church is therefore a sufficient evidence of Christian doctrine, not that of individual writers, who are to be regarded rather so far as they testify the catholic doctrine, than as they propound their own.[74] This deference to an imaginary perfection in the church of the fourth or fifth century must have given a great advantage to that of Rome, which is not always weak on such ground, and doubtless serves to account for those frequent desertions to her banner, especially in persons of very high rank, which afterwards occurred in Germany. [72] Nostri e quibus olim multi ibidem absolutum decretum approbarunt, paulatim ad sententiam primorum quatuor sæculorum, nempe decretum juxta præscientiam factum, receperunt. Qua in re multum egregiè laboravit Ægidius Hunnius. Difficile autem est hanc sententiam ita proponere, ne quid Pelagianismo habere affine videatur, p. 14.