This book situates Saint Ignatius of Loyola’s classic fourteen Rules for the Discernment of Spirits within the larger Catholic spiritual tradition. Each chapter provides a brief explanation of the rule in question and then presents the parallel wisdom of other saints and spiritual figures. A fundamental truth about Ignatius’ rules underlies this approach: He helps us grasp, often for the first time, the spiritual experience that always occurs in our hearts and thoughts. In his rules, Ignatius describes universal spiritual experiences. We find similar teaching from other spiritual writers and saints that appear in this book, including Augustine, Francis of Assisi, Thomas Aquinas, Thomas à Kempis, Teresa of Avila, John of the Cross, Thérèse of Lisieux, Francis de Sales, and more. Ignatius’ rules are “Ignatian” only in formulation, in their structure and their wording; the experience he describes is that of every disciple of Jesus. Ignatius’ gift, guided by the Holy Spirit, was to perceive this experience clearly and express it succinctly, in an eminently practical way. This book offers the best way of amplifying Ignatius’ highly compact text, drawing on the wider Catholic spiritual tradition with many great spiritual writers.