MANDUKYA UPANISHAD : Chapter-1. "AGAMA PRAKARANA" ( The Scriptural Treatise ) Mantram-2, Discussion- 9.
( The Scriptural Treatise )
"Sarvam hyetad Brahma, ayam-atma Brahma,
so' yam-atma catuspat."
sarvam - all;
hi - indded;
brahma - this (is) BRAHMAM;
ayam atma brahma - this Self ( ATMA IN US ) is BRAHMAM;
sah - That ( BRAHMAM );
ayam atma - ( which is ) this Self ( ATMA IN US );
catuspat - ( is ) covered with four quarters ( PARTS ).
"All this is verily BRAHMAM. This is BRAHMAM. This JIVATMA ( ATMA WITHIN US ) has four quarters ( parts )."
From the smoke rolling up in the distant valleys, we conclude that there is fire in it.
So too, we witness inert matter vitalised to activity and playing the part of sentience, we conclude that there must be Pure Sentience in contact with the dynamic matter.
Thus the only method available for the Rishi-s in making us understand the Reality is through its own activity, perceptible and dynamism, in and through matter wh…