Sattva is a noun built on the participle sat (or sant), from as, the verb 'to be.' Sat means 'being; as it should be; good, well, perfect,' and sattva, accordingly, 'the ideal state of being; goodness, perfection, crystal purity, immaculate clarity, and utter quiet.'
Zimmer provides the etymological and ontological foundation for sattva, establishing it as the guna of luminous clarity that facilitates enlightenment and must be cultivated through Yoga practice.
, Philosophies of India, 1951thesis