Mbh 12.194.2c

The Intelligence that exists in a living creature concerns itself with the three states (called Passion, Darkness, and Goodness). Sometimes it obtains joy and sometimes misery. Sometimes it becomes divested of both joy and misery. Even thus the Intelligence exists in the minds of all men. Sometimes the Intelligence which is made up of the triple states (already mentioned), transcends those three states (by yoga), like the lord of rivers, viz., the Ocean, with his surges, transgressing his high continents.[607] That Intelligence which transcends the three qualities exists in the mind in a pure state of (unmodified) existence alone. The quality of Darkness, however, that impels to action, soon pursues it. At that time, the Intelligence sets all the senses to action. The properties of the three are even thus: joy dwells in Goodness; sorrow in Passion; delusion in Darkness. All the states that exist (of the mind) are included in the three (that have been named). I have now, O Bharata, told thee about the course of the Understanding. An intelligent man should subdue all his senses. The three qualities of Goodness, Passion, and Darkness, are always attached to living creatures. Three kinds of intelligence also are noticeable in every creature, viz., that which depends upon Goodness, that upon Passion, and that upon Darkness, O Bharata. The quality of Goodness brings happiness; the quality of Passion produces sorrow; and if these two combine with the quality of Darkness, then neither happiness nor sorrow is produced (but, instead, only delusion or error). Every state of happiness that appears in the body or the mind is said to be due to the quality of Goodness. A state of sorrow, disagreeable to oneself, that comes, is due to nothing but the quality of Passion. One should never think of it with fear.