During the past century the textual criticism and literary history of the Penitentials have received considerable attention, but the investigation of their actual function in social and church life has only begun. Yet the field is inviting. The Penitentials have, for instance, notable legal and economic aspects; they offer considerable information on ascetic practices, they have a bearing on ritual developments; and the relation of their relaxations, compositions and commutations of penance to the development of Indulgences is itself an important question. It is not the purpose of the present article to investigate any of these, but to suggest still another angle of approach. I wish to present some elementary considerations toward the answer to a question which is perhaps more basic than any of those just suggested. The question may be stated thus: What did the Penitentials contribute, and what were they designed to contribute, to the cure of souls? The cure of souls (cura animarum ) means of course the general ministry of religion in the care, and only incidentally the healing, of souls. But the penitent was regarded as one morally diseased and ill, and his treatment is, in the Penitentials, repeatedly, even habitually, referred to as the task of the moral physician. His sins are the symptoms of disease. The penalties enforced are “medicamenta,” “remedia,” “fomenta”—measures designed to restore his moral and spiritual health.