Is the use of leavened bread in the East because they think the bread used at the Institution was leavened or for some other reason?
Aquinas (PLEASE don't make me look it up!) says that a valid Eucharist can be celebrated with leavened bread, but it would by naughty for a Catholic to do so, while not naughty for a Greek, because of the disciplines of their respective communions.
My church uses unleavened bread, so if "my argument" is in favor of leavened, I'd be at odds with my own church. I wondered when & where the difference came about. Mind you though, I am troubled by the Normans trying to enforce their standard on all others. Things that generate a blood trail give me pause.
Against it is that the Last Supper is understood to have been a Passover meal.
Makes perfect sense to me.
Is the use of leavened bread in the East because they think the bread used at the Institution was leavened or for some other reason?
One of the Oriental churches claim their leavening was passed down from one of the Apostles. It was distributed to all of the members of the church, so they were able to fulfill one of their responsibilities, bring the bread & wine to church for the communion. The cynic in me would like to test the DNA of the leavening in various locations.
For what it's worth, (wiki was my source here) "Those who use leavened bread see the leaven as a symbol of resurrection and new life, and concomitantly associate its lack with mourning."
Aquinas (PLEASE don't make me look it up!) says that a valid Eucharist can be celebrated with leavened bread, but it would by naughty for a Catholic to do so, while not naughty for a Greek, because of the disciplines of their respective communions.
Naughty? lol
Can. 926 According to the ancient tradition of the Latin Church, the priest is to use unleavened bread in the eucharistic celebration whenever he offers it.