“Robert Burton's The Anatomy of Melancholy (1621) was a profoundly important analysis of human states of mind - a kind of early philosophical/ psychological study. He sees 'melancholy' as part of the human condition, especially love melancholy and religious melancholy. His concerns are remarkably close to those which Shakespeare explores in his plays. Ambition, for example, Burton describes as 'a proud covetousness or a dry thirst of Honour, a great torture of the mind, composed of envy, pride and covetousness, a gallant madness' - words which could well be applied to Macbeth.”