1. The principles and practices of an ascetic or extreme self-denial and austerity.
2. The doctrine that the ascetic life (rigorous self-denial, abstinence) releases the soul from bondage to the body and permits union with the divine.

Originally, an ascetic was someone who practiced the mode of life of a hermit or a monk, characterized by solitude, meditation, prayer, toil, fasting, and celibacy.

Implicit in this lifestyle of self-discipline and self-denial is the idea that the pleasures of this world should be renounced in favor of a "higher" purpose; such as, intellectual discipline or spiritual insight.