Before the “complementary and alternative medicine” fad, and before UFO craze, lived a man whom you might call the first modern pseudoscientist.

His name was Immanuel Velikovsky. He had a strange theory about a comet—that turned out to be Venus—shaping the course of human history.

He tangled with Carl Sagan about it—and with the scientific community about it. And then, he was mostly forgotten.

But no longer, because Princeton historian of science Michael Gordin has tracked down Velikovsky’s personal papers. In his book The Pseudoscience Wars: Immanuel Velikovsky and the Birth of the Modern Fringe, Gordin uses Velikovsky’s example to show how he laid the groundwork for other pseudosciences-it’s kind of like they followed in his footsteps.

Michael Gordin is professor of history at Princeton University and director of the program in Russian and Eurasian Studies. He has written widely in the history of science with a focus on the Soviet Union and the early nuclear age. The Pseudoscience Wars is his fourth book.