We have to assign its authorship to Moses, because of the difficulty of otherwise accounting for it. That it was a spontaneous decree of the people, produced by their confidence in the national god after their victory over the Egyptians, is very improbable. Many reasons, however, can be given for its having been decreed by Moses. The explanation just mentioned is more probable when applied to him. He may, as Professor Kuenen conjectures,[5] have regarded the national success as a proof of the greatness of the national god, and so have vowed the people to his exclusive service. The connection between this hypothesis and the idea of a covenant between Jahveh and Israel, to be referred to presently, is in its favour. But a stronger reason for believing the commandment to be due to Moses might be found in his desire to secure the national unity. The Israelites had grown so numerous as to be divided into separate tribes. If the people had more gods than one, the old process would be repeated, each tribe choosing a different god for its tribal deity; and thus their religion would help the tendency towards disunion. We know how the unity of Greece was anything like a reality only when it was based on the worship of Apollo at Delphi, Apollo becoming practically the national god of the Hellenes.[6] If no rivals of Apollo had existed, how much more effective his worship would have been! In general it may be said that, in an early stage of political development, national unity can be secured against tribal separation only by basing it on religion. A close union was specially necessary to the Israelites at this time, when they had to struggle against so many peoples in order to obtain a home. Recognizing the impossibility of otherwise securing this union, Moses may well have framed the first commandment in order to give the tribes at least one bond of union in the exclusive worship of Jahveh, their national god. We may conclude, then, that from the Mosaic age it was part of the Israelitic religion that the tribal, or national, god should be worshipped exclusively. The people, whatever might be their practice, had accepted the principle. The second and third commandments, which prohibit idolatry and the misuse of Jahveh’s name, are evidently meant to be supports of the first, by demanding reverence for Jahveh and by abolishing the records of his rivals. The next two are merely local. But the last five, the second table of the law, are the basis of a feature of the Jewish religion even more important than its monotheism.