Douglas Harper's Etymology Dictionary
"truth" (in Hindu philosophy), from Sanskrit sattvah "truth," literally "being," cognate with Gothic sunjis, Old English soð "true" (see sooth).
n. One of the three gunas in Hindu philosophy, representing things that are pure, divine, and spiritual.
Sattva ( Sanskrit: सत्त्व) is one of the three Guṇas (tendencies, qualities, attributes), a philosophical and psychological concept developed by the Samkhya school of Hindu philosophy. The other two qualities are rajas (passion and activity) and tamas (destruction, chaos). Sattva is the quality of goodness, positivity, truth, wholesomeness, serene, holistic, creative, constructive, balance, confidence, peaceful, virtuous, drawn towards Dharma and Jnana (knowledge).