5. If we narrow our field and look, not at the whole Church, but at the Churches of Asia Minor and Syria, we may obtain yet another certainty from the obscure period which lies between the age of the Apostles and that of Dionysius and Irenæus. The investigations of Lightfoot, Zahn, and Harnack have placed the genuineness of the short Greek form of the Epistles of Ignatius beyond reasonable dispute. Their exact date cannot as yet be determined. The evidence is strong that Ignatius was martyred in the reign of Trajan: and, if that is accepted, the letters cannot be later than A.D. 117. But even if this evidence be rejected as not conclusive, and the letters be dated ten or twelve years later, their testimony will still be of the utmost importance. They prove that long before A.D. 150 episcopacy was the recognized form of government throughout the Churches of Asia Minor and Syria; and, as Ignatius speaks of "the bishops that are settled _in the farthest parts of the earth_ (κατὰ τὰ πέρατα ὁρισθέντες)" they prove that, according to his belief, episcopacy was the recognized form everywhere (_Ephes._ iii.). This evidence is not a little strengthened by the fact that, as all sound critics on both sides are now agreed, the Epistles of Ignatius were evidently not written in order to magnify the episcopal office, or to preach up the episcopal system. The writer's main object is to deprecate schism and all that might tend to schism. And in his opinion the best way to avoid schism is to keep closely united to the bishop. Thus, the magnifying of the episcopal office comes about incidentally; because Ignatius takes for granted that everywhere there is a bishop in each Church, who is the duly appointed ruler of it, loyalty to whom will be a security against all schismatical tendencies. These four or five points being regarded as established to an extent which may reasonably be called certainty, there remain certain other points about which certainty is not yet possible, some of which admit of a probable solution, while for others there is so little evidence that we have to fall back upon mere conjecture. Among these would be the distinctions of office, or gradations of rank, among the clergy in the first century or century and a half after the Ascension, the precise functions assigned to each office, and the manner of appointment. With regard to these questions three positions may be assumed with a considerable amount of probability.