Abstract
" Id efficit quod figurat " is the definition of the sacrament that came to the fore in the Christian Middle Ages, setting it down in its dual "cognitive" and "operative" function: it is a sign, and it performs what it signifies. Theologians theorized the conditions for the efficacy of the sacramental sign, proposing sometimes contradictory analyses of the various elements involved in this act, which is at once the work of God as primary cause, and of human actors as secondary causes: the primary institution, the ecclesial institution, the priest (his function, his intention, his act), the recipient, the formula (its linguistic form, its enunciation), the ritual, and so on. These conditions will serve as a reference, explicitly or tacitly, for thinking about other speech acts, whether authorized or forbidden (exorcisms, blessings, oaths, vows, prayers, invocations, curses, incantations, magic words).
