The object of this study is to outline, as straightforwardly as possible, the whole range of the philosophical work by Rudolf Steiner. These works were far ahead of their time and not widely recognized, remaining virtually unknown to most modern philosophers. Steiner’s later works of spiritual science and their practical manifestation in many aspects of life—including education, agriculture, and medicine—are nevertheless gaining increasing interest. In this context, his philosophy, which lays the foundation for all that followed, needs to be widely understood. Because this philosophy describes Steiner’s living experiences of the physical and invisible worlds, the author places it in the context of a brief biography to show how Steiner’s thinking developed. – Richard Seddon’s studies in moral sciences convinced him that Rudolf Steiner’s resolution of the main problems of philosophy since Aristotle was correct. After a half century of subsequent work in anthroposophy, he saw the need for an introductory volume that clearly lays out Steiner’s views without the complications that arise in the context of late nineteenth-century philosophy. This book is the result, intended both for students of anthroposophy who have no knowledge of philosophy and for students of philosophy who have no knowledge of anthroposophy.