This one comes to us from the mind of Sharon (thanks, Sharon!): Man Who Was Thursday by
G. K. Chesterton.
FROM THE PUBLISHER
Perhaps best-known to the general public for his Father Brown detective series, G. K. Chesterton was renowned for his wit, rhetorical brilliance, and talent for ingenious paradox. Those qualities are lavishly displayed in this funny, fast-paced novel about a club of anarchists in turn-of-the-twentieth-century London. Ostensibly a story of mystery and espionage, it's also--on a deeper level--a vehicle for social, religious, and philosophical commentary.