The 2013 Marjorie Grene Prize -- for the best manuscript based on a presentation at one of the two previous ISHPSSB meetings by someone who was, at the time of presentation, a graduate student -- will be shared between two recipients: a historian, Lukas Rieppel; and a philosopher, John Matthewson. The full citation is online at http://ishpssb.org/2013-marjorie-grene-prize-citation/.