For what is Baldassar Castiglione known?

One of the most prominent proponents of illusion was the author Baldassar Castiglione who wrote The Book of the Courtier in 1528 to provide advice on how to behave properly in all situations. Castiglione is a proponent of honor and duty but asserts that a man must use tactics of mild deception at times in order to gain personal and business advantage.