This brief but multifaceted study looks to the sources of the Christian spiritual tradition in order to establish a firm ground for a vital contemporary Christian spirituality. Quoting the great Jesuit scientist and mystic Teilhard de Chardin, "Everything is the sum of the past, nothing is comprehensible except through its history, " author George Lane, SJ, examines the masters of Christian spirituality in their historical contexts. Fr. Lane shows why the hermits of the East, the monks of the West, Origen, Jerome, Augustine, Francis, and many others were so influential in their times and what they can teach us today about Christian spirituality.