According to Roman Catholicism, Sacred Tradition and the Bible together provide the foundation of spiritual truth. From this combination the Catholic church has produced many doctrines which it says are true and biblical but which Protestants reject: veneration of Mary, penance, indulgence, purgatory, prayer to saints, et. al. Protestantism, however, rejects these doctrines, and Roman Catholic Sacred Tradition, and holds fast to the call "Sola Scriptura," or, "Scripture Alone." Catholics then challenge, "Is Sola Scriptura biblical?"