Luther applied those principles to the reformation of the Church in his book on the _Babylonian Captivity of the Church_ (Sept.-Oct. 1520). He subjected the elaborate sacramental system of the Church to a searching criticism, and concluded that there are only two, or perhaps three, scriptural sacraments—the Eucharist, Baptism, and Penance. He denounced the doctrine of Transubstantiation as a “monstrous phantom” which the Church of the first twelve centuries knew nothing about, and said that any endeavour to define the precise manner of Christ’s Presence in the sacrament is simply indecent curiosity. Perhaps the most important practical portion of the book deals with the topic of Christian marriage. In no sphere of human life has the Roman Church done more harm by interfering with simple scriptural directions: “What shall we say of those impious human laws by which this divinely appointed manner of life has been entangled and tossed up and down? Good God! it is horrible to look upon the temerity of the tyrants of Rome, who thus, according to their caprices, at one time annul marriages and at another time enforce them. Is the human race given over to their caprice for nothing but to be mocked and abused in every way, that these men may do what they please with it for the sake of their own fatal gains? ... And what do they sell? The shame of men and women, a merchandise worthy of these traffickers, who surpass all that is most sordid and most disgusting in their avarice and impiety.” Luther points out that there is a clear scriptural law on the degrees within which marriage is unlawful, and says that no human regulations ought to forbid marriages outside these degrees or permit them within. He also comes to the conclusion that divorce _a mensa et thoro_ is clearly permitted in Scripture; though he says that personally he hates divorce, and “prefers bigamy to it.” The appeal _To the Christian Nobility of the German Nation_ made the greatest immediate impression. It was written in haste, but must have been long thought over. Luther began the introduction on June 23rd (1520); the book was ready by the middle of August; and by the 18th, four thousand copies were in circulation throughout Germany, and the presses could not print fast enough for the demand. It was a call to all Germany to unite against Rome. It was nobly comprehensive: it grasped the whole situation, and summed up with vigour and clearness all the German grievances which had hitherto been stated separately and weakly; it brought forward every partial proposal of reform, however incomplete, and quickened it by setting it in its proper place in one combined scheme. All the parts were welded together by a simple and courageous faith, and made living by the moral earnestness which pervaded the whole.