OPUS OPERATUM. Work wrought, as though it were said that the benefit of a rite accrued ex opere operato, by virtue of the work wrought, i.e. by virtue of the due administration. The doctrine meant by the expression opus operatum was first enunciated in form by the Schoolman Duns Scotus  (ob. 1308), who thus wrote (as Robertson translates): "A sacrament confers grace through the virtue of the work which is wrought, so that there is not required any inward good motion such as to deserve grace, but it is enough if the receiver place no bar" in the way of its operation.  The doctrine thus stated makes the passive reception of a sacrament sufficient, and if it does not intentionally teach that the ordinance works mechanically like a charm, it must inevitably spread among ordinary people the perilous notion that it does. The German Schoolman Gabriel Biel (ob. 1495), taught the doctrine in no more guarded a way, though avoiding some dangerous expressions, saying that ex opere operato meant "by virtue of the very consecration, oblation, and reception, of the venerable eucharist...."
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