We read in the Chândogya (I, 9), 'What is the origin of this world?' 'Ether,' he replied. 'For all these beings spring from the ether only, and return into the ether. Ether is greater than these; ether is their rest.' Here there arises the doubt whether the word 'ether' denotes the well-known element or Brahman.--The Pûrvapakshin maintains the former alternative. For, he says, in the case of things to be apprehended through words we must accept that sense of the word which, proved by etymology, is immediately suggested by the word. We therefore conclude from the passage that the well-known Ether is the cause of the entire aggregate of things, moving or non-moving, and that hence Brahman is the same as Ether.--But has it not been shown that Brahman is something different from non-sentient things because its creative activity is preceded by thought?--This has been asserted indeed, but by no means proved. For the proper way to combine the different texts is as follows. Having been told that 'that from which these beings are born is Brahman', we desire to know more especially what that source of all beings is, and this desire is satisfied by the special information given by the text, 'All these things spring from the ether.' It thus being ascertained that the ether only is the cause of the origin, and so on, of the world, we conclude that also such general terms as 'Being' ('Being only was this in the beginning') denote the particular substance called 'ether.' And we further conclude that in passages such as 'the Self only was all this in the beginning', the word 'Self (âtman) also denotes the ether; for that word is by no means limited to non-sentient things--cp., e.g., the phrase, 'Clay constitutes the Self of the jar'--, and its etymology also (âtman from âp, to reach) shows that it may very well be applied to the ether. It having thus been ascertained that the ether is the general cause or Brahman, we must interpret such words as 'thinking' (which we meet with in connexion with the creative activity of the general cause) in a suitable, i.e. secondary, or metaphorical sense. If the texts denoted the general cause by general terms only, such as 'Being', we should, in agreement with the primary sense of 'thinking', and similar terms, decide that that cause is an intelligent being; but since, as a matter of fact, we ascertain a particular cause on the basis of the word 'ether', our decision cannot be formed on general considerations of what would suit the sense.--But what then about the passage, 'From the Self there sprang the ether' (Taitt. Up. II, 1, 1), from which it appears that the ether itself is something created?--All elementary substances, we reply, such as ether, air, and so on, have two different states, a gross material one, and a subtle one. The ether, in its subtle state, is the universal cause; in its gross state it is an effect of the primal cause; in its gross state it thus springs from itself, i.e. ether in the subtle state.