How is strength of the will possible? Concerning Francis of marchia and the act of the will

Francis of Marchia dealt at length in several different contexts with the nature of the will and willing. Here I examine just one of those discussions: the possibility for the will to go against reason's final judgment, a topic related to weakness of will and the source of sin. Marchia is clearly of a voluntaristic bent, holding that the will can indeed act against the determination of reason. After examining Marchia's argumentation for his position, I explore some of the background to Marchia's view in a distinctively later medieval understanding of the human mind as a system of internal acts and dispositions, with the possibility that several of them belong to the same faculty simultaneously. This increasingly complex conceptualisation of the mind mirrors a new, more complex conceptualization of the "Self".