The problem of the history of Yahwism depends essentially upon the view adopted as to the date and origin of the biblical details and their validity for the various historical and religious conditions they presuppose. Yahwism is a religion which appears upon a soil saturated with ideas and usages which find their parallel in extra-biblical sources and in neighbouring lands. The problem cannot be approached from modern preconceptions because there was much associated with the worship of Yahweh which only gradually came to be recognized as repugnant, and there was much in earlier ages and in other lands which reflects an elevated and even complex religious philosophy. In the south of the Sinaitic peninsula, remains have been found of an elaborate half-Egyptian, half-Semitic cultus (Petrie, _Researches in Sinai_, xiii.), and not only does Edom possess some reputation for "wisdom," but, where this district is concerned, the old Arabian religion (whose historical connexion with Palestine is still imperfectly known) claims some attention. The characteristic denunciations of corruption and lifeless ritual in the writings of the prophets and the emphasis which is laid upon purity and simplicity of religious life are suggestive of the influence of the nomadic spirit rather than of an internal evolution on Palestinian soil. Desert pastoral life does not necessarily imply any intellectual inferiority, and its religious conceptions, though susceptible of modification, are not artificially moulded through the influence of other civilizations. Nomadic life is recognized by Arabian writers themselves as possessing a relative superiority, and its characteristic purity of manner and its reaction against corruption and luxury are not incompatible with a warlike spirit. If nomadism may be recognized as one of the factors in the growth of Yahwism, there is something to be said for the hypothesis which associates it with the clans connected with the Levites (see E. Meyer, _Israeliten_, pp. 82 sqq.; B. Luther, ib. 138). It is, however, obvious that the influence due to immigrants could be, and doubtless was, exerted at more than one period (see §§ 18, 20; also HEBREW RELIGION; PRIEST).