It may be worth while, in conclusion, to note that the comparative prosperity or progressiveness of Islam as a proselytizing and civilizing force in Africa--a phenomenon regarded even by some Christians with satisfaction, and by some with alarm [1192]--is not strictly or purely a religious phenomenon. Moslem civilization suits with negro life in Africa in virtue not of the teaching of the Koran, but of the comparative nearness of the Arab to the barbaric life. He interbreeds with the natives, fraternizes with them (when not engaged in kidnapping them), and so stimulates their civilization; where the European colonist, looking down on them as an inferior species, isolates, depresses, and degrades them. It is thus conceivable that there is a future for Islam at the level of a low culture-stage; but the Arab and Turkish races out of Africa are rather the more likely to concur in the rationalistic movement of the higher civilization. Even in Africa, however, a systematic observer notes, and predicts the extension of, "a strong tendency on the part of the Mohammedans towards an easy-going rationalism, such as is fast making way in Algeria, where the townspeople and the cultivators in the more settled districts, constantly coming in contact with Europeans, are becoming indifferent to the more inconvenient among their Mohammedan observances, and are content to live with little more religion than an observance of the laws, and a desire to get on well with their neighbours." [1193] Thus at every culture-level we see the persistence of that force of intellectual variation which is the subject of our inquiry. CHAPTER IX CHRISTENDOM IN THE MIDDLE AGES It would be an error, in view of the biological generalization proceeded on and the facts noted in this inquiry, to suppose that even in the Dark Ages, so called, [1194] the spirit of critical reason was wholly absent from the life of Christendom. It had simply grown very rare, and was the more discountenanced where it strove to speak. But the most systematic suppression of heresies could not secure that no private heresy should remain. As Voltaire has remarked, there was "nearly always a small flock separated from the great." [1195] Apart too from such quasi-rationalism as was involved in semi-Pelagianism, [1196] critical heresy chronically arose even in the Byzantine provinces, which by the curtailment of the Empire had been left the most homogeneous and therefore the most manageable of the Christian States. It is necessary to note those survivals of partial freethinking, when we would trace the rise of modern thought. § 1. HERESY IN BYZANTIUM