Francis of Marchia (fl. 1320) is best known in the history of science as having posited several radically unAristotelian cosmological views, but over the past 15 years scholarly attention has also been focused on other areas of his thought from modal theory to trinitarian theology. This volume capitalizes on these studies and on recent critical editions of some of Marchia's works, presenting six articles by foremost specialists on some of Marchia's often distinct and influential doctrines in cosmology, physics, metaphysics, ethics, and politics. The articles in the volume show that Marchia made interesting, and sometimes influential, contributions in all these areas. An "Introduction" to the volume as a whole situates Marchia in his scholarly context, and gives an exhaustive bibliography of Marchia studies.