From the time she was a young child, Catherine of Siena (1347-1380) sought God ceaselessly in both contemplation and action. By the time she was twenty-one, she had experienced her mystical marriage to Christ, and she had thrown herself tirelessly into ministering to the poor and the sick. Throughout her active ministry, Catherine pursued eternal truth through prayer, reading, and ecstatic experiences. While in an ecstatic trance, Catherine dictated The Dialogue — presented here, in mildly modernized, edited form. In this intense and searching work, the saint of Siena offers up petitions to God, filling her conversation with instruction on discernment, true and false spiritual emotion, obedience and truth. Catherine’s brilliant insights into the nature of the spiritual life and the character of the Church will motivate contemporary Christians who seek to unite a life of prayer with a life of action.