It is not enough to keep the Commandments, though we must; it is not enough to love one another as ourselves, though we must. The one thing needful, the unum necessarium of the Kingdom, is to love as He loves us, which is the love of joy in suffering and sacrifice, like Roland and Olivier charging into battle to their death defending those they love as they cry "Mon joie"; that is the music of Christian Culture.
The Restoration of Christian Culture (1983)