The masterpiece of G. K. Chesterton’s distinguished literary career, this treatise mounts a defense of Christianity. The author employs the term orthodoxy as a synonym for right opinion, and he applies the concept of correct reasoning to his formal and scholarly arguments, which are expressed in down-to-earth language. Chesterton’s thought-provoking analogies, personal anecdotes, and engaging humor make this polemic a work of enduring charm and persuasion.