In this episode we read the Catechism’s explanation concerning why Christ chose bread and wine for the matter for the sacrament of his body and blood. The Catechism also discusses not only the particular suitability of bread and wine- but also why the bread should be unleavened (in the Latin Rite) and why there should be water mingled with it. In addition we read several articles from the Summa Theologica concerning this same subject. (ST IIIa Q. 74, a.1-a.6)