Properly analyzed, the collective mythological and religious writings of humanity reveal that around 1500 BC, a comet swept perilously close to Earth, triggering widespread natural disasters and threatening the destruction of all life before settling into solar orbit as Venus, our nearest planetary neighbor. Sound implausible? Well, from 1950 until the late 1970s, a huge number of people begged to differ, as they devoured Immanuel Velikovsky's major best-seller, Worlds in Collision, insisting that perhaps this polymathic thinker held the key to a new science and a new history. Scientists, on the other hand, assaulted Velikovsky's book, his followers, and his press mercilessly from the get-go. In The Pseudoscience Wars, Michael D. Gordin resurrects the largely forgotten figure of Velikovsky and uses his strange career and surprisingly influential writings to explore the changing definitions of the line that separates legitimate scientific inquiry from what is deemed bunk, and to show how vital this question remains to us today. Drawing on a wealth of previously unpublished material from Velikovsky's personal archives, Gordin presents a behind-the-scenes history of the writer's career, from his initial burst of success through his growing influence on the counterculture, heated public battles with such luminaries as Carl Sagan, and eventual eclipse. Along the way, he offers fascinating glimpses into the histories and effects of other fringe doctrines, including creationism, Lysenkoism, parapsychology, and more—all of which have surprising connections to Velikovsky's theories. Science today is hardly universally secure, and scientists seem themselves beset by critics, denialists, and those they label "pseudoscientists"—as seen all too clearly in battles over evolution and climate change. The Pseudoscience Wars simultaneously reveals the surprising Cold War roots of our contemporary dilemma and points readers to a different approach to drawing the line between knowledge and nonsense.