Now, taking all these data together, we find here, just as we did in the previous section, that the Levitical law is a disturbing element between Exodus and Deuteronomy. If we take it out of the way, J, E, and D harmonise well enough. The main difference is that the latter shows the same fundamental conditions as we find in the former, only consolidated and developed by time, but by a longer time than forty years. In fact D makes explicit that importance of the Levites which is only hinted at and foreshadowed in JE. They have come to be the only authorised agents of sacrifice; they have a hereditary headship in the house of Aaron; various orders and degrees must be held to exist (cf. Deut. xviii. 1 ff.). Compared with this state of things, the Levitical arrangements of P, supposed to have been given thirty-eight years before, are very different. In every respect they are more definite, more detailed, and show a much more differentiated organisation than those sketched in Deuteronomy. These latter indicate a state of matters which would suit admirably as an embryonic stage of the full-grown Levitical system, and which can hardly be fitted into their place otherwise. It is suggested, in reply, that allusions in Deuteronomy _imply_ the existence of a system of a much more elaborate kind than any that we could construct from the explicit statements of the book, and that is certainly true. But no reasonable interpretation of these allusions can lead us to a system identical with that in P. Nor can Deuteronomy's use of the name Levites (though undoubtedly it has been pressed by some too far) be held to be consistent with the public recognition of the "great gulf fixed" in P between the Aaronic priests and the Levites as a body. Nor will the fact that Deuteronomy is the people's book, and is consequently not called upon to go into technical details, cover the difference. Indeed nothing will, short of recognising the fact that, as publicly acknowledged organisations, the tribe of Levi in P and the tribe of Levi in D are different, and that the state of things in D's day is earlier than that in P. If this is not so, then the Levitical legislation, conceived as given by Moses, must be held to have proved impracticable, and Deuteronomy must then be regarded as an abrogation of it for the time.