The 'but' sets aside the pûrvapaksha. There is no truth in the assertion
that from the designation of the Highest as a bridge (or bank) it
follows that there is something beyond the Highest. For Brahman in that
text is not called a bank with regard to something to be reached thereby;
since the additional clause 'for the non-confounding of these worlds'
declares that it is compared to a bridge or bank in so far as it binds
to itself (setu being derived from _si_, to bind) the whole aggregate of
sentient and non-sentient things without any confusion. And in the
clause 'having passed beyond that bridge' the _passing beyond_ means
_reaching_; as we say, 'he passes beyond the Vedanta,' meaning 'he has
fully mastered it.'