Creator ineffabilis

Creator ineffábilis (Latin for "O Creator Ineffable") is a prayer composed by the 13th century Doctor of the Church St. Thomas Aquinas. It is also called the "Prayer of the St. Thomas Aquinas Before Study" (Latin: Oratio S. Thomae Aquinatis ante studium) because St. Thomas "would often recite this prayer before he began his studies, writing, or preaching." Pope Pius XI published this prayer in his 1923 encyclical letter on St. Thomas Aquinas, Studiorum Ducem.