The Understanding, living in individual Soul, exists in three states. Sometimes she rejoices, sometimes she grieves, and sometimes she exists in a state which is neither pleasure nor pain. Having for her essence these states, of Sattva, Rajas, and Tamas), the Understanding passes through these three states.
पुरुष तिष्ठती बुद्धिस्त्रिषु भावेषु वर्तते। कदाचिल्लभते प्रीति कदाचिदपि शोचति॥ न सुखेन न दुःखेन कदाचिदपि वर्तते। सेयं भावात्मिका भावांस्त्रीनेतान् परिवर्तते॥