The Epistles of the Brethren of Purity: Lost Encyclopedia of Islamism on Philosophy and Sciences
More than a thousand years ago, the Epistles of the Brethren of Purity—a sophisticated encyclopedia—was written by an enigmatic group, still a mystery today. In history, people feared the knowledge in these Epistles so much that they wanted it destroyed. Why is this encyclopedia that important? What is so special about it?