18.20 Viddhi, know; tat, that; jnanam, knowledge, realization of the Self as non-dual, complete realization; to be sattvikam, originating from sattva; yena, through which knowledge; iksate, one sees; ekam, a single; avyayam, undecaying-that which does not undergo mutation either in itself or by the mutation of its alities-' i.e. eternal and immutable; bhavam, Entity-the word bhava is used to imply an entity-, i.e. the single Reality which is the Self; sarvabhutesu, in all things, in all things begining from the Unmanifest to the unmoving things; and through which knowledge one sees that Entity to be avibhaktam, undivided; in every body, vibhaktesu, in all the deversified things, in the different bodies. The idea is: that Reality which is the Self remains, like Space, undivided.
Being based on rajas and tamas, those that are the dualistic philosophies are incomplete, and hence are not by themselves adeate for the eradication of worldly existence.