As they develop the New Testament’s analogy between health of the body and salvation of the soul, the Fathers of the Church organize three types of “passages” of different nature : metaphors transpose the structures of what can be observed (the visible) to what cannot be (the unvisible) ; they provide semantic resources to express the modes of the exchanges between Heaven and Earth, between the worldly life and the “true life” ; but they also seem to have some consequences on the very conceptions of health and illness, the evolutions of which are significant of the transition from Antiquity to the Middle Ages. (Abstract provided by the author)