The state of being tranquil (sama) in Hinduism is referred to as Shanti Vritti – having total indifference towards worldly life. It is one of the many senses in which the term Shanti is used. In the system of Advaita Vedanta, one of the prerequisites for the realization of Brahman is to remain tranquil. The term Shanti is derived from the Sanskrit root ‘sam’, meaning to be calm or quiet.
In order to gain cessation from worldly existence, there are four basic requirements to be fulfilled, namely, discrimination between the eternal and perishable matter, detachment from sensual pleasures in this and the next world, possession of six virtues, and desire for liberation. The six virtues are dama (self-restraint), sama (tranquility), uparati (absence of all desires), titiksha (forbearance), samadhana (concentration) and Shraddha (faith).
All that perseverance aims at is attaining the bliss of atma in perfect shanty. A popular saying in Sanskrit states that one who is calm in his younger days is calm and wonders who will not be calm when there is depletion of strength in the body.
The Shanti Parva of the Mahabharata, perhaps, bears its name because it contains such advice as would lead to tranquility of mind. While Bharata, in his popular Sanskrit treatise on dramaturgy, Natyashastra, holds the view that there are eight sentiments (rasa) to be portrayed in a Sanskrit drama, Anandavardhana, a later rhetorician, includes Shanta as the ninth sentiment, citing the Mahabharata as the authority. Upanishads generally begin and end with Shantipath, - the recitation of Shanti Mantra.