Book excerpt: This book examines the relationship between magic, philosophy and the investigation of nature in presocratic Greece. Did the presocratic thinkers, often praised for their rejection of the supernatural, still believe in gods and the divine and the efficacy of magical practices? Did they use animism, astrology, numerology and mysticism in their explanations of the world? This book analyses the evidence in detail and argues that we need to look at each of these beliefs in context.