Searching for a better description of this rotting sadness, I came upon the concept of acedia. In Christian theology, it’s an antecedent to sloth, the least sexy of the seven deadly sins. Thomas Aquinas winnowed it down for me: acedia is sorrow so complete that the flesh prevails completely over the spirit. You don’t just turn your back on the world, you turn your back on God. You don’t care, and you don’t care that you don’t care.