Saint Thomas Aquinas

Because he was big and strong and sometimes slow to speak, Thomas Aquinas’s schoolmates called him the Dumb Ox. Not long afterward, he came to be called Doctor (which means “teacher”) because he could actually understand complicated things quickly and explain them well.

Which is what he loved to do, preaching often and writing in the course of his lifetime no fewer than eighty-five works of philosophy and theology — books that changed the Church and the world. Indeed, in 1320, less than fift...