William George Ward's Essays on the Church's Doctrinal Authority is a collection of 19th-century theological essays focusing on the concept of the Church's doctrinal authority, emphasizing the infallibility of the Church's definitions of doctrine, with in-depth arguments about the extent to which this authority extends to the Church's definitions and teachings, often addressing the themes of the Church's unity and the importance of apostolic tradition. Ward argues that the Church is not only infallible on fundamental matters of faith, but also possesses broad definitional infallibility, a key concept in Roman Catholic theology. The essays are an intellectual defense of the Church's position on establishing doctrine, demonstrating that acceptance of this authority is essential to true faith.