The purvapakshin maintains that, in accordance with the ordinary meaning of the term, pra/n/a denotes the air with its five modifications, that the word ‘thunderbolt’ also is to be taken in its ordinary sense, and that thus the whole passage contains a glorification of air.  For, he says, this whole world trembles, abiding within air with its five forms—­which is here called pra/n/a—­and the terrible thunderbolts also spring from air (or wind) as their cause.  For in the air, people say, when it manifests itself in the form of Parjanya, lightning, thunder, rain, and thunderbolts manifest themselves.—­Through the knowledge of that air immortality also can be obtained; for another scriptural passage says, ’Air is everything by itself, and air is all things together.  He who knows this conquers death.’—­We therefore conclude that the same air is to be understood in the passage under discussion.

To this we make the following reply.—­Brahman only can be meant, on account of what precedes as well as what follows.  In the preceding as well as the subsequent part of the chapter Brahman only is spoken of; how then can it be supposed that in the intermediate part all at once the air should be referred to?  The immediately preceding passage runs as follows, ’That only is called the Bright, that is called Brahman, that alone is called the Immortal.  All worlds are contained in it, and no one goes beyond it.’  That the Brahman there spoken of forms the topic of our passage also, we conclude, firstly, from proximity; and, secondly, from the circumstance that in the clause, ’The whole world trembles in pra/n/a’ we recognise a quality of Brahman, viz. its constituting the abode of the whole world.  That the word pra/n/a can denote the highest Self also, appears from such passages as ‘the pra/n/a of pra/n/a’ (B/ri/.  Up.  IV, 4, 18).  Being the cause of trembling, moreover, is a quality which properly appertains to the highest Self only, not to mere air.  Thus Scripture says, ’No mortal lives by the pra/n/a and the breath that goes down.  We live by another in whom these two repose’ (Ka.  Up.  II, 5 5).  And also in the passage subsequent to the one under discussion, (’From terror of it fire burns, from terror the sun burns, from terror Indra and Vayu, and Death as the fifth run away,’) Brahman, and not the air, must be supposed to be spoken of, since the subject of that passage is represented as the cause of fear on the part of the whole world inclusive of the air itself.  Thence we again conclude that the passage under discussion also refers to Brahman, firstly, on the ground of proximity; and, secondly, because we recognise a quality of Brahman, viz. its being the cause of fear, in the words, ’A great terror, a raised thunderbolt.’  The word ‘thunderbolt’ is here used to denote a cause of fear in general.  Thus in ordinary life also a man strictly carries out a king’s command because he fearfully considers in his mind, ’A thunderbolt (i.e. the king’s wrath, or threatened