In three sweeping essays written for our current moment of scientific mistrust, Thomas Levenson searches for the origin points of the most common arguments against that they are unnatural; that they are more dangerous than the illnesses they claim to prevent; and that they are an affront to freedom. Each arose from the earliest development of particular vaccines and the campaigns to distribute them. What surprises Levenson, though, even as the pattern repeats, is how innocent the skepticism initially was and, in each case, how very human fears and questions ultimately turned into something darker, where no truth would be enough to overcome the doubt.