A Course in Miracles (often called just “the Course”) is a self-study course for retraining the mind that is spiritual, rather than religious, in its perspective. Although it uses Christian terminology, it is ecumenical in its approach, and its underlying ontology is reminiscent of ancient refrains, echoing the world’s most hallowed traditions. The Course is pragmatic in its method, and its aim is a peaceful mind: “Knowledge is not the motivation for learning this course. Peace is.” Nevertheless, the Course frequently emphasizes its simplicity. The edition of A Course in Miracles that is reproduced in this volume is sometimes referred to as the Hugh Lynn Cayce version because, upon completion, it had been delivered to Hugh Lynn Cayce, son of the renowned psychic Edgar Cayce, in 1972, before the manuscript was subjected to the substantial editing process that is described below.