Before he became the guru of an entire generation, Dr. Timothy Leary, who passed away in 1996, was a renowned Harvard psychologist whose studies continue to have a strong influence on psychology today. Unfortunately, Leary is often remembered far too little for his groundbreaking research and much more for his role in the last cultural revolution. In his main work "Info-Psychology," Leary describes the theory of the eight neural circuits as well as consciousness, providing the first quantitative developmental model of consciousness, which can indeed be compared to Spiral Dynamics from Don Beck and Clare Graves or the works of Ken Wilber. Both amusing and provocative, visionary and deeply insightful, Leary here outlines a perspective on human evolution that may only be fully appreciated in many years to come.