Thomas Watson is one of the most famous Puritan preachers in history, and his writings during the 17th century are still read across the world today. He was a prodigious writer whose works include All Things for Good (originally published as A Divine Cordial), The Ten Commandments, and more.
The Art of Divine Contentment is a study of one of Paul's letters to the Philistines, and the notion that being discontent is a sin. As part of the answer, Watson suggests, "The way for a man to be contented is not by raising his estate higher, but by bringing his heart lower."