The Rev. Father Joseph Simler was a priest and author of the nineteenth and twentieth centuries. In addition to serving as Superior General for the Society of Mary, he also released a Catechism of Mental Prayer, which received a third edition in 1911 through the Brothers of Mary. Father Simler\'s work is a concise and easily-readable book that explains in detail what is involved with mental prayer, also known as meditation. It was printed by TAN in 2010 with the Nihil Obstat and Imprimatur.