This spiritual autobiography was originally intended as a series of addresses to the nuns of the Order of the Discalced Carmelites, the order which St Teresa founded. The book contains advice and direction on themes ranging from self-knowledge and humility to detachment and suffering. St Teresa compares the human soul to a castle, equipped with many mansions. The key to entering this castle is prayer. Following St Teresa's spiritual pilgrimage, the reader enters the first mansion of humility and then the succeeding manions of practising prayer, meditation, the prayer of quiet, the prayer of union with God, before entering the central mansion where God resides and where the most special spiritual blessings are to be received.