The history of the Near East during the last three centuries before the Christian era is the history of the gradual passing of Asiatic religions westward to occupy the Hellenic vacuum, and of Hellenic philosophical ideas eastward to supplement and purify the religious systems of West Asia. How far the latter eventually penetrated into the great Eastern continent, whether even to India or China, this is no place to discuss: how far the former would push westward is written in the modern history of Europe and the New World. The expansion of Mithraism and of half-a-dozen other Asiatic and Egyptian cults, which were drawn from the East to Greece and beyond before the first century of the Hellenistic Age closed, testifies to the early existence of that spiritual void in the West which a greater and purer religion, about to be born in Galilee and nurtured in Antioch, was at last to fill. The instrumentality of Alexander and his successors in bringing about or intensifying that contact and intercourse between Semite and Greek, which begot the philosophic morality of Christianity and rendered its westward expansion inevitable, stands to their credit as a historic fact of such tremendous import that it may be allowed to atone for more than all their sins.
This, then, the Seleucids did--they so brought West and East together that each learned from the other. But more than that cannot be claimed for them. They did not abolish the individuality of either; they did not Hellenize even so much of West Asia as they succeeded in holding to the end. In this they failed not only for the reasons just considered--lack of vital religion in their Macedonians and their Greeks, and deterioration of the Hellenism of Hellenes when they ceased to be citizens of free city-states--but also through individual faults of their own, which appear again and again as the dynasty runs its course; and perhaps even more for some deeper reason, not understood by us yet, but lying behind the empirical law that East is East and West is West.
As for the Seleucid kings themselves they leave on us, ill-known as their characters and actions are, a clear impression of approximation to the traditional type of the Greek of the Roman age and since. As a dynasty they seem to have been quickly spoilt by power, to have been ambitious but easily contented with the show and surface of success, to have been incapable and contemptuous of thorough organization, and to have had little in the way of policy, and less perseverance in the pursuit of it. It is true that our piecemeal information comes largely from writers who somewhat despised them; but the known history of the Seleucid Empire, closed by an extraordinarily facile and ignominious collapse before Rome, supports the judgment that, taken one with another, its kings were shallow men and haphazard rulers who owed it more to chance than to prudence that their dynasty endured so long.