Depression’s Upside - NYTimes.com

Depression’s Upside - NYTimes.com: "For Darwin, depression was a clarifying force, focusing the mind on its most essential problems. In his autobiography, he speculated on the purpose of such misery; his evolutionary theory was shadowed by his own life story. “Pain or suffering of any kind,” he wrote, “if long continued, causes depression and lessens the power of action, yet it is well adapted to make a creature guard itself against any great or sudden evil.”"