About Dan Attrell David Porreca is Associate Professor of Classical Studies and codirector of the Medieval Studies program at the University of Waterloo and is president of the Societas Magica. Books by Dan Attrell On the Christian Religion by (author) Marsilio Ficino introduction and notes by Dan Attrell, Brett Bartlett & David Porreca Picatrix A Medieval Treatise on Astral Magic translated by Dan Attrell & David Porreca