In 1927, Ralph W. Stephenson published Chiropractic Textbook, one of the historic Palmer Green Books and the first systematic presentation of chiropractic philosophy. Its thirty-three principles became a foundation of classical chiropractic thought.From Source to Periphery revisits Stephenson's work through the perspective of modern physiology, neuroscience, and clinical reasoning. It examines which concepts remain relevant, which require reinterpretation, and which should be reconsidered in light of contemporary knowledge.Across 34 chapters, Stephenson's philosophy is connected with present-day clinical practice through modern commentary, comparison tables, case discussions, key points, and review questions.Written for students and practitioners of chiropractic, osteopathic manual therapy, and related professions, this book bridges the philosophical foundations of 1927 with the science and clinical reasoning of today.Volume 5 of the PCC PRESS Clinical Reasoning Series.