We now leave behind us the beliefs and practices of savage and barbarous tribes, and turn to those of mighty empires. The gulf which lies between these two parts of our subject is obviously a wide one; and in many instances there is no bridge by which the student can pass from one to the other. Often it is a matter of inference rather than of direct proof that the great systems are built out of the materials accumulated, as we have seen, in the prehistoric period. But the inference is sufficiently strong to rest upon; in some cases we are able to see quite clearly how the religion of the empire arose by an uninterrupted growth out of that of the tribe; and in the cases where this cannot be so fully made out, we yet judge that the result came about in a similar way. We pause therefore at this point to ask what is the nature of the transition at which we have arrived, or, in other words, what constitutes the difference between the primitive and the later religions? The difference is probably not one of magnitude only; it consists not merely in the fact that the religion of the empire is that of a much larger number of people than that of the tribe; there is a difference in character as well as in dimensions. With a view to the examination of this point it will be found convenient to consider some of the proposed classifications of religions, as most of these, though for different reasons, place the religions of the early world in a different category from those known to us historically. The old-fashioned Classification of Religions was that of the true and the false. This our principle forbids us to accept, since we regard the various faiths of the world as stages in the development of religion, and therefore all relatively true.