The fourth chapter of the Book of Ezra introduces the vexed question of the limits of comprehension in religion by affording a concrete illustration of it in a very acute form. Communities, like individual organisms, can only live by means of a certain adjustment to their environment, in the settlement of which there necessarily arises a serious struggle to determine what shall be absorbed and what rejected, how far it is desirable to admit alien bodies and to what extent it is necessary to exclude them. The difficulty thus occasioned appeared in the company of returned exiles soon after they had begun to rebuild the temple at Jerusalem. It was the seed of many troubles. The anxieties and disappointments which overshadowed the subsequent history nearly all of them sprang from this one source. Here we are brought to a very distinguishing characteristic of the Persian period. The idea of Jewish exclusiveness which has been so singular a feature in the whole course of Judaism right down to our own day was now in its birth-throes. Like a young Hercules, it had to fight for its life in its very cradle. It first appeared in the anxious compilation of genealogical registers and the careful sifting of the qualifications of the pilgrims before they left Babylon. In the events which followed the settlement at Jerusalem it came forward with determined insistence on its rights, in opposition to a very tempting offer which would have been fatal to its very existence. The chronicler introduces the neighbouring people under the title "The adversaries of Judah and Benjamin"; but in doing so he is describing them according to their later actions; when they first appear on his pages their attitude is friendly, and there is no reason to suspect any hypocrisy in it. We cannot take them to be the remainder of the Israelite inhabitants of the Northern Kingdom who had been permitted to stay in their land when their brethren had been violently expelled by the Assyrians, and who were now either showing their old enmity to Judah and Benjamin by trying to pick a new quarrel, or, on the other hand, manifesting a better spirit and seeking reconciliation. No doubt such people existed, especially in the north, where they became, in part at least, the ancestors of the Galileans of New Testament times. But the men now referred to distinctly assert that they were brought up to Palestine by the Assyrian king Esar-haddon. Neither can they be the descendants of the Israelite priests who were sent at the request of the colonists to teach them the religion of the land when they were alarmed at an incursion of lions;[27] for only one priest is directly mentioned in the history, and though he may have had companions and assistants, the small college of missionaries could not be called "the people of the land" (ver. 4). These people must be the foreign colonists. There were Chaldæans from Babylon and the neighbouring cities of Cutha and Sepharvaim (the modern _Mosaib_), Elamites from