Temperance is fourteen, the proportion found; the Devil is fifteen, the addiction that follows losing it. The composition is deliberately the Lovers': a man, a woman, a large presence between them — only the angel is now a devil and the two trees are two chains. That's the mechanism: the Devil is the Lovers' shadow — the same union, one chosen, the other clung to. And the chains around their necks are loose, liftable at any moment, and they haven't lifted them.
Where you'll recognise it: knowing it's bad and continuing, saying 'I can't' when you mean 'I don't want to', and everything that comforts you briefly and shrinks you over time. This card is about the power of matter and appetite — not bad, just very strong, and very good at disguising itself as necessity.
Running well (the Devil has a well), it's owning your appetite, your body, your shadow, without pretending they aren't there. Stuck, its problem is mistaking the chain for fate — 'that's just how I am', 'there's no choice' — when every one of those lines is a choice. The Devil's whole power rests on your believing the chain is locked.
