The study of heresy and heterodoxy and of belief in magic, witchcraft and the devil has in the past 25 years made significant advances in our understanding of art and iconography, ideas, mentality and belief, and ordinary life and popular imagination in the patristic and medieval periods. At the forefront of research into this aspect of medieval intellectual history has been Jeffrey B. Russell, whose numerous books and articles have opened important new paths in the field. To mark his retirement 17 established and emerging scholars from Europe and North America - historians of art, the church, religions, and ideas - have contributed papers on the many areas which Russell has influenced. Topics dealt with include elves, the Christians apocrypha, mysticism, sexuality, heresies and heresiologies, apocalyptic tracts, astrology, hell, and other Christian encounters with non-believers. These essays are offered as tribute to the deep impact that Russel has had on medieval studies. Contributors include: Alan Bernstein, Richard Emmerson, Alberto Ferreiro, Neil Forsyth, Abraham Friessen, Karen Jolly, Henry Ansgar Kelly, Richard Kieckhefer, Beverly M. Kienzle, Garry Macy, Bernard McGinn, Edward Peters, Cheryl Rigs, Larry J. Simon, Laura Smoller, Catherine B. Tkacz, and John Tolan.