Thomas Cajetan
Thomas Cajetan (; 20 February 14699 August 1534), also known as Gaetanus, commonly Tommaso de Vio or Thomas de Vio, was an Italian philosopher, theologian, cardinal (from 1517 until his death) and the Master of the Order of Preachers 1508 to 1518. He was a leading theologian of his day who is now best known as the spokesman for Catholic opposition to the teachings of Martin Luther and the Protestant Reformation while he was the Pope's Legate in Augsburg, and perhaps also among Catholics for his extensive commentary on the "Summa Theologica" of Thomas Aquinas.