Whether this sacrament ought to be made of unleavened bread?

❌ Objection 1 : It seems that this sacrament ought not to be made of unleavened bread. because in this sacrament we ought to imitate Christ's institution. But Christ appears to have instituted this sacrament in fermented bread, because, as we have read in Ex. 12, the Jews, according to the Law, began to use unleavened bread on the day of the Passover which is celebrated on the fourteenth day of the moon; and Christ instituted this sacrament at the supper which He celebrated "before the festival day of the Pasch" (Jn. 13:1,4). Therefore we ought likewise to celebrate this sacrament with fermented bread.

❌ Objection 2 : Further, legal observances ought not to be continued in the time of grace. But the use of unleavened bread was a ceremony of the Law, as is clear from Ex. 12. Therefore we ought not to use unfermented bread in this sacrament of grace.

❌ Objection 3 : Further, as stated above (Question [65], Article [1]; Question [73], Article [3]), the Eucharist is the sacrament of charity just as Baptism is the sacrament of faith. But the fervor of charity is signified by fermented bread, as is declared by the gloss on Mt. 13:33: "The kingdom of heaven is like unto leaven," etc. Therefore this sacrament ought to be made of leavened bread.

❌ Objection 4 : Further, leavened or unleavened are mere accidents of bread, which do not vary the species. But in the matter for the sacrament of Baptism no difference is observed regarding the variation of the accidents, as to whether it be salt or fresh, warm or cold water. Therefore neither ought any distinction to be observed, as to whether the bread be unleavened or leavened.