Albert Gallatin Mackey

Albert Gallatin Mackey was an American medical doctor and author. He is best known for his writing many books and articles about freemasonry, particularly the Masonic Landmarks. He acquired the Greek, Latin, Hebrew, and continental languages almost unaided, and lectured frequently on the intellectual and moral development of the Middle Ages. Subsequently, he turned his attention exclusively to the investigation of abstruse symbolism, and to cabalistic and Talmudic researches.

---Wikipedia