§ 167.4. =Unionist Efforts.=--The distinguished theologian Chr. Matt. Pfaff, chancellor of the University of Tübingen, who, without being numbered among the pietists, recognised in pietism a wholesome reaction against the barren worship of the letter which had characterized orthodoxy, regarded a union between the Lutheran and Reformed churches on their common beliefs, which in importance far exceeded the points of difference, as both practicable and desirable; and in A.D. 1720 expressed this opinion in his “_Alloquium Irenicum ad Protestantes_,” in which he answered the challenge of the “_Corpus Evangelicorum_” at Regensburg (§ 153, 1). His proposal, however, found little favour among Lutheran theologians. Not only Cyprian of Gotha, but even such conciliatory theologians as Weismann of Tübingen and Mosheim of Helmstädt [Helmstadt], opposed it. But forty years later a Lutheran theologian, Heumann of Göttingen, demonstrated that “the Reformed doctrine of the supper is true,” and proposed, in order to end the schism, that Lutherans should drop their doctrine of the supper and the Reformed their doctrine of predestination. This pamphlet, edited after the author’s death by Sack of Berlin, in A.D. 1764, produced a great sensation, and called forth a multitude of replies on the Lutheran side, the best of which were those of Walch of Jena and Ernesti of Leipzig. Even within the Lutheran church, however, it found considerable favour. § 167.5. =Theories of Ecclesiastical Law.=--Of necessity during the first century of the Protestant church its government was placed in the hands of the princes, who, because there were no others to do so, dispensed the _jura episcopalia_ as _præcipua membra ecclesiæ_. What was allowed at first in the exigency of these times came gradually to be regarded as a legal right. Orthodox theology and the juristic system associated with it, especially that of Carpzov, justified this assumption in what is called the =episcopal system=. This theory firmly maintains the mediæval distinction between the spiritual and civil powers as two independent spheres ordained of God; but it installs the prince as _summus episcopus_, combining in his person the highest spiritual with the highest civil authority. In lands, however, where more than one confession held sway, or where a prince belonging to a different section of the church succeeded, the practical difficulties of this theory became very apparent; as, _e.g._, when a Reformed or Romish prince had to be regarded as _summus episcopus_ of a Lutheran church. Driven thus to seek another basis for the claims of royal supremacy, a new theory, that of the =territorial system=, was devised, according to which the prince possessed highest ecclesiastical authority, not as _præcipuum membrum ecclesiæ_, but as sovereign ruler in the state. The headship of the church was therefore not an independent