Deo iudicio percusset – Study on the idea of contamination after supplication and papal letters. Canon law defines a perfect idea of the cleric’s body, far away from scandal or stain, whereas the Church’s appraisal of responsibility in the incapacity is a key factor allowing to understand how dispensations were granted. These were required to ask the Pope for dispensations in order to contravene the canon law and the Church norm, demanded by the circumstances of their disability. Layman could also asked for such dispensation to go against Lent, Church feed ban or religious vows they took when they were healthy. Papal dispensation letters, written in answer to such petitions, offered us a significant insight into the Church’s comprehension of contamination, to show how one could get a disease, linked with complexion theory or related to God. Thus, this article highlights the incorporation of disease seen by a complexity of medical discourse during the 13th and 14th centuries and a new clerical and secular understanding and approach of etiology.