acedia: To Aquinas, the melancholy condition of acedia [from the Greek for “absence of care”] which afflicted solitary Christian monks and hermits—causing them to apathetically shirk work and seek “undue rest”—is a sin. Walter Benjamin noted that acedia had re-emerged, among sophisticated urbanites in 19th century Paris, as ennui; and Aldous Huxley described it as a “subtle and complicated vice,” composed of boredom, sorrow, and despair at the futility of everything.
The Idler’s Glossary