The first question respecting each one of the Christian writings seems to have been: "Was it written by an apostle?" If this question could be answered in the affirmative, the book was admitted. And in deciding this question, the Christians of later times made appeal to the opinions of those of earlier times; authority and tradition had much to do in determining it. "Was it the general opinion of the early church that this book was written by an apostle?" they asked. And if this seemed to be the case, they were inclined to admit it. Besides, they compared Scripture with Scripture: certain books were unquestionably written by Paul or Luke or John; other books which were doubted were also ascribed to them; if they found the language of the disputed book corresponding to that of the undisputed book, in style and in forms of expression, they judged that it must have been written by the same man. Upon such grounds of external and internal evidence, it finally came to be believed that all of the New Testament books except four were written by apostles, and that these four, Mark, Luke, The Acts of the Apostles, and the Epistle to the Hebrews, were written by men under the immediate direction of apostles. But, it may be said, there have been great differences of opinion on this matter through all the ages, down to the sixteenth century; how do we know but that those good and holy men, like Ignatius and Clement and Tertullian and Origen in the early church, and Luther and Zwingli and Œcolampadius in the Reformed church, were right in rejecting some books that we receive and in receiving some that we reject? If you were a good Catholic, that question would not trouble you. For the fundamental article of your creed would then be, The Holy Catholic Church, when she is represented by her bishops in a general council, can never make a mistake. And the Holy Catholic Church in a general council at Trent, in 1546, said that such and such books belonged to the Bible, and that no others do; and the council of the Vatican, in 1870, said the same thing over again, making it doubly sure; so, that, as a good Catholic, you would have no right to any doubts or questions about it. But, being a Protestant, you cannot help knowing that all general councils have made grave and terrible mistakes; that no one of them ever was infallible; and so you could not rest satisfied with the decisions of Trent and the Vatican, even if they gave you the same Bible that you now possess, which, of course, they do not. What certainty has the Protestant, then, that his canon is the correct one? He has no absolute certainty. There is no such thing as absolute certainty with respect to historical religious truth. But this discussion has made one or two things plain to the dullest apprehension.