And now again we see how inevitably the force of attraction correlates with the force of repulsion. The new channels of the spirit of union, being dug not by reason but by ignorance, become new channels for the reverse flow of the spirit of strife; and as sectarian zeal spreads, in the absence of openings, good or bad, for public spirit, there arise new forms of domestic hate and struggle. Crude religious fervours, excluding, or arising in lack of, the play of the saner and higher forms of thought and feeling, beget crude antipathies;[68] and Christianity leads back to bloody strifes and seditions such as had not been seen since the fall of the Republic. There is not intellectuality enough to raise men above this new superinduced barbarism of ignorant instinct; half of the old Christendom, disintegrated like the old politics, is overrun by a more robust barbarism that adopts a simpler creed; and the new barbaric Christendom exhibits in its turn all the modes of operation of the biological forces that had been seen in the old. § 5 Thus far we have considered Roman evolution in terms of a moral estimate of the reactions of classes. But lest we lose sight of the principle of total causation, it is fitting to restate the process in terms of that conception, thus explaining it non-morally. We may view Rome, to begin with, as a case of the unique aggrandisement of a State in virtue of fit conditions and institutions. Thus (1) the comparatively uncommercial situation of the early Latins, leaving them, beyond cattle-breeding and agriculture, no occupation save war for surplus energy, and no readier way of acquiring wealth;[69] (2) the physical collocation of a group of seven defensive hills, so close that they must be held by a federated group;[70] (3) the ethnic collocation of a set of tribe groups of nearly equal vigour and ardour, strengthening each other's sinews by constant struggling; (4) the creation (not prescient, but purely as a provision against kingship) of the peculiar institution of the annual consulate,[71] securing a perpetuity of motive to conquest and a continuous flow of administrative energy;[72] (5) the peculiar need, imposed by this very habit of all-round warfare, for accommodation between the ruling and ruled classes, and for the safeguarding of the interests of the latter by laws and franchises; (6) the central position of Rome in Italy, enabling her to subdue it piecemeal; and finally (7) the development by all these means of a specialist aristocracy, habitually trained to administration[73]--all these genetic conditions combined to build up the most remarkable military empire the world has ever seen. They obtrude, it is clear, half of the explanation of the fact that the Romans rose to empire where the much more early civilised Greek cities of Italy did not.