TRANSUBSTANTIATION, the term adopted by the Ro man Catholic Church to express her teaching on the subject of the conversion of the Bread and Wine into the Body and Blood of Christ in the Eucharist. Its signification was authoritatively de fined by the Council of Trent in the following words : "If any one shall say that, in the Holy Sacrament of the Eucharist there re mains, together with the Body and Blood of Our Lord Jesus Christ, the substance of the Bread and Wine, and shall deny that wonderful and singular conversion of the whole substance of the Bread into (His) Body and of the Wine into (His) Blood, the species only of the Bread and Wine remaining—which conversion the Catholic Church most fittingly calls Transubstantiation—let him be anathema." (Sess. xiii. can. 2.) The word Transubstan tiation is not found earlier than the 12th century. But in the Eucharistic controversies of the 9th, loth and 11th centuries the views which the term embodies were clearly expressed; as, for example, by Radbertus Paschasius (d. 865), who wrote that "the substance of the Bread and Wine is efficaciously changed interiorly into the Flesh and Blood of Christ," and that of ter the consecra tion what is there is "nothing else but Christ the Bread of Heaven." The words "substantially converted" appear in the formula which Berengarius was compelled to sign in ion. We may take it that the first use of the word is in a passage of Hildebert de Savardin (d. 1133), who brings it into an exhortation quite infor
mally, as if it were in common use. It is met with in a Decretal of Innocent III. The fourth Lateran Council fully adopted it (1215). It is clear from the treatise of Radbertus Paschasius already quoted that the word "substance" was used for reality as distinguished from outward appearance, and that the word "spe cies" meant outward appearance as opposed to reality. The terms, therefore, were not invented by St. Thomas Aquinas, and are not mere scholastic subtlety. The definition of the Council of Trent was intended both to enforce the accepted Catholic position and to exclude the teaching of Luther, who, whilst not professing to be certain whether the "substance" of the Bread and Wine could or could not be said to remain, exclaimed against the intolerance of the Roman Catholic Church in defining the question.