Flesh and Blood vs Rigor of Justice The Concepts of Justitia and Aequitas in “Processus Satanae contra genus humanum”

Abstract

A fifteenth-century treatise, Processus Satanae contra genus humanum, is a peculiar artefact of late medieval culture as it blends theological, theatrical, and juridical elements significant for the period. Intended as a manual for law students, it provided an idealized example of an ordinary court hearing. According to the plot, the Devil files a complaint against the entire humankind and demands that it returns to his possession. He sends a demonic representative to defend his interests, while the Virgin Mary assumes the role of humankind's lawyer. The trial is presided by Jesus Christ the judge. After an exhausting debate, the forces of good win the case. Underneath this entertaining and grotesque façade lies a serious discussion about different types of justice and their importance for a real-life judge, lawyer, or plaintiff. The author of Processus Satanae distinguishes two types of justice — justitia and aequitas. Justitia refers to rigorous justice of human law, while aequitas refers to righteousness coupled with mercy. The latter comes directly from God; without aequitas, justitia becomes rigid law that has no real power in Christian sense. Since the Devil and his servant rely exclusively on justitia, as they do not know misery and empathy, they ultimately lose the case. In this way, the treatise warns law students against following the letter of law blindly and without regard for individual circumstances.