When one is ready to tolerate all kinds of sufferings in order to control the senses and keep the mind steady, that is called titikṣā, or tolerance. And when one can control the urges of the tongue and genitals, that is called dhṛtiḥ. From dhṛtiḥ, one becomes dhīra, pacified. A pacified person is never disturbed by the urges of the tongue and the genitals.
If one can fix his mind on Kṛṣṇa without deviation, he can attain a steadfast position in Kṛṣṇa consciousness, śānta-rasa. When one attains śānta-rasa, unflinching faith in Kṛṣṇa is established, and all material desires cease. These specific characteristics of śānta-rasa—unflinching faith in Kṛṣṇa and cessation of all desires which are not connected with Kṛṣṇa—are common to all other rasas as well, just as sound is generally present in all other elements (air, fire, water and earth) because it is produced from the sky.