Nearly six hundred years ago, a short, genial, cannily alert man in his late thirties took a very old manuscript off a library shelf, saw with excitement what he had discovered, and ordered that it be copied. That book was the last surviving manuscript of an ancient Roman philosophical epic, On the Nature of Things, by Lucretius—a beautiful poem of the most dangerous ideas: that the universe functioned without the aid of gods, that religious fear was damaging to human life, and that matter was made up of very small particles in eternal motion, colliding and swerving in new directions. One of the world’s most celebrated scholars, Stephen Greenblatt, PhD, Cogan University Professor of the Humanities, Harvard University, has crafted both an innovative work of history and a thrilling story of discovery in his book The Swerve, in which one manuscript, plucked from a thousand years of neglect, changed the course of human thought and made possible the world as we know it.  This program, to be held Monday, January 27 beginning at 7 pm in the Hunnewell Building of the Arnold Arboretum, is as of this date full.  However, it is winter, and people go to Florida, get a cold, or don’t feel like digging out the car, so call 617-384-5277, or email  //adulted@arnarb.harvard.edu to join the waiting list. Include names/# of tickets desired, phone and email address.