Answer
Ngô Đình Diệm was a Vietnamese nationalist who served as the first President of South Vietnam from 1955 until his assassination in 1963. Diệm was a devout Catholic and a supporter of the Personalist philosophy of French philosopher Emmanuel Mounier. Diệm's political doctrine, Person Dignity Theory, was based on the belief that the individual is the highest value in society and that the state should exist to serve the people.