Book excerpt: The Philokalia is a collection of texts on prayer and the spiritual life, written between the fourth and fifteenth centuries by masters of the Orthodox Christian tradition. First published in Greek in 1782, translated into Slavonic and later into Russian, this is the first complete translation into English. It is made from the original Greek, and will be completed in five volumes. Volume IV contains some of the most important writings in the entire collection. St Symeon the New Theologian speaks about the conscious experience of the Holy Spirit and about the vision of the divine and uncreated Light. St Gregory of Sinai provides practical guidance concerning the life of the Hesychast and the use of the Jesus Prayer. St Gregory Palamas discusses the distinction between the essence and the energies of God.