In this book, Immanuel Velikovsky, in his unmistakably clear and unique style, relates both the writing of and the reaction to the publication of his epochal work Worlds in Collision. Through authentic letters, we experience at first hand the beginning and unfolding of the Velikovsky Affair - from the boycotting of his publisher by leading American scientists and universities to the emotional and highly unscientific campaign to discredit the author and his work. We also get to read Velikovsky's rebuttals to the attacks and accusations, which were mostly denied publication by relevant journals and magazines. Especially today, with the power and societal influence of science at an all-time high, this book is of fundamental importance for our understanding of science and its practioners.