Upeksa

 (Sanskrit/Devanāgarī script: ; Pali: Upekkhā), is the Buddhist concept of equanimity. The Tibetan equivalent is བཏང་སྙོམས་ btang snyoms. This is a purifying mental state cultivated through meditation on the Buddhist path to prajñā (wisdom) and bodhi (enlightenment). The analogous term in Greek philosophy is ataraxia.

Pali literary contexts
In the Pali Canon and post-canonical commentary, upekkha is identified as an important step in one's spiritual development in a number of places:
 * It is one of the Four Sublime States (brahmavihara), which are purifying mental states capable of counteracting the defilements of lust, avarice and ignorance. As a brahmavihara, it is also one of the forty traditionally identified subjects of Buddhist meditation (kammatthana).
 * In the development of meditative concentration, upekkha arises as the quintessential factor of material absorption, present in the third and fourth jhana states.
 * In the Seven Factors of Enlightenment (bojjhanga), upekkha is the ultimate factor to be developed.
 * In the Theravada list of ten paramita (perfections), upekkha is the last-identified bodhisatta practice.

Contemporary exposition
American Buddhist monk Bhikkhu Bodhi wrote:
 * “The real meaning of upekkha is equanimity, not indifference in the sense of unconcern for others. As a spiritual virtue, upekkha means equanimity in the face of the fluctuations of worldly fortune. It is evenness of mind, unshakeable freedom of mind, a state of inner equipoise that cannot be upset by gain and loss, honor and dishonor, praise and blame, pleasure and pain. Upekkha is freedom from all points of self-reference; it is indifference only to the demands of the ego-self with its craving for pleasure and position, not to the well-being of one's fellow human beings. True equanimity is the pinnacle of the four social attitudes that the Buddhist texts call the 'divine abodes': boundless loving-kindness, compassion, altruistic joy, and equanimity. The last does not override and negate the preceding three, but perfects and consummates them.”