 Moral and spiritual theories also prevailed, and in the Christian environment of medieval Europe, a malaise called "acedia" (sloth or absence of caring) was identified, involving low spirits and lethargy typically linked to isolation.The seminal scholarly work of the 17th century was English scholar Robert Burton's book, "The Anatomy of Melancholy", drawing on numerous theories and the author's own experiences.Burton suggested that melancholy could be combatted with a healthy diet, sufficient sleep, music, and "meaningful work", along with talking about the problem with a friend.