His disastrous Letterman interview brought Joaquin Phoenix's whole quitting-acting-to-become-a-bearded-rapper shtick to a dizzying climax last night. Dave played it off as legit. Others think it's all an Andy Kaufman-esque hoax. We think it's both!

TMZ and our sister from another, Quaadlude-riddled mother Defamer are heavy on the hoax beat. 'Cause, you know, Casey Affleck is filming a documentary of Phoenix's transition from good if not very well liked actor to his new rapper persona: Old Sergeant MacGruffin', a Civil War soldier who got lost in the Great Smoky Mountains for 140 years. So it must be some sort of mockumentary thing and there will be a big "ha ha" and then Phoenix will go back to being an actor, still as good, probably, and definitely still not very well liked. And I believe that!

But I also believe that there's a current of sincerity in the whole debacle, not really born out of an actual desire to become a rapper, but stemming from a great desire for more and more precious drugs. Phoenix's cataclysm on Letterman last night came freighted with the usual "nervous tics" of people currently on or desperately awaiting their next dance with heroin. And like the junkies on The Wire were always cooking up harebrained schemes to go rob junkyards or drug stashes, a rich smackhead with a lot of time on his hands might decide that it makes complete sense to make some gonzo comedy/art project about being a rapper. And then maybe said golden triangulist might start to buy into the whole act a bit too much, because they're crazy and on drugs all the time. That would explain his highly-focused commitment to the act, even while he's being eviscerated by David Letterman. (Or maybe Letterman was in on it!)

The only thing tough to reconcile is Casey Affleck's involvement. If Phoenix really is on drugs, Affleck is kind of a shitty friend for indulging the whole Rip van Tinkle experience. Hopefully, in defense of a world I like to imagine where Casey Affleck is still a nice boy from Cambridge, Phoenix really is a nut, but sober as can be, who is just now finally showing the effects of growing up in the supremely bizarre way that he did. If that's the case, then godspeed. Just don't do anymore national television. It makes me uncomfortable.