The Philosophy of the Upanishads c5.s1.1.3

c5.s1.1.3

If, however, these two factors that determined the arrangement, namely, the tendency to a systematic classification of the material for instruction and the preservation of the order of chronological development, do actually for the most part coincide in their result, this is very simply explained on the supposition that in the course of time the general interest was transferred from the ritualistic method of treatment to the allegorical, and from that again to the philosophical. Moreover, the separation of the material is by no means strictly carried out, but in all three classes, Brâhmaṇas, Âraṇyakas, and Upanishads, there are found occasionally digressions of a ritual as well as allegorical or philosophical nature. Especially noteworthy, however, and demanding explanation is the circumstance that, apart from this occasional overlapping of the subject-matter, the broad distinctions between Brâhmaṇa Âraṇyaka and Upanishad are by no means always correctly observed; e.g., among the Aitareyins the matter of the Brâhmaṇa extends into the Âraṇyaka, while with the Taittirîyakas the close of the Brâhmaṇa and the beginning of the Âraṇyaka agree throughout, and the dividing line is entirely arbitrary.