A mystical practice in the Eastern Orthodox Church dating back to the 10th century that aims to bring about inner quietness and divine contemplation. It comes from a Greek word hesychia which means “quietude” or “silence.” It traces its origins to spiritual practices in the 4th century among the Desert Fathers. Its primary method is the repetition of a short prayer, “Lord Jesus Christ, son of God, have mercy on me," during each breathing cycle. The mind should be empty of other thoughts. This method is similar to eastern meditational practices involving the use of mantras that are repeated during the inhalation and exhalation.
In the 14th century, Hesychasm was attacked by an Italian cleric, Barlaam of Calabria, who brought charges of heresy against one of its advocates, Gregory Palmas (1296-1359), who was later to become Archbishop of Thessalonica. The latter defended the practice, and his views were later confirmed by three synods in Constantinople. Hesychasm became an official practice of the Orthodox Church and became popular, especially after the publication of a collection of texts called the Philokalia in Russia in 1782.