The Philosophy of the Upanishads c6.s2.1

c6.s2.1

Owing to the manner in which the Upanishads have arisen from the activity of the different Vedic schools and their intercourse one with another, we are unable to lay down any precise chronological order of succession among them. All the principal Upanishads contain earlier and later elements side by side, and therefore the age of each separate piece must be determined by itself as far as this is possible from the degree of development of the thoughts which find expression in it. Here, where we still treat of the Upanishads as a whole, we can only attempt a rough and approximate determination of the period to which in general an Upanishad belongs.