With the fledgling Institute experiencing an uncertain future, John Baptist de La Salle joined Brothers Nicholas Vuyart and Gabriel Drolin in privately pronouncing what later was known as the Heroic Vow. In doing so, they promised to maintain the schools, even if they had to live on bread alone.

Brother Jose Maria Valladolid, Lasallian Chronology: Documented Events in the Life of Saint John Baptist de La Salle (Rome: Brothers of the Christian Schools, 1994), p. 121..