A leavening agent is an organism or substance that when added to a dough[?] of flour and water causes it to "rise" by evolving carbon dioxide or other gasses that become trapped as bubbles[?] within the dough.
... He was a follower of Geert Groote
and Florentius Radewijns, the founders of the
Brethren of the Common Life. His writings are
all of a devotional ...