The seven thains of Morgoth

[obloquy]

Melkor had corrupted many spirits — some great, as Sauron, or less so, as Balrogs. The least could have been primitive (and much more powerful and perilous) Orcs; but by practising when embodied procreation they would (cf. Melian) [become] more and more earthbound, unable to return to spirit-state (even demon-form), until released by death (killing), and they would dwindle in force. When released they would, of course, like Sauron, be 'damned': i.e. reduced to impotence, infinitely recessive: still hating but unable more and more to make it effective physically (or would not a very dwindled dead Orc-state be a poltergeist?).

Myths Transformed

I just found this little bit. It seems to lend at least some support to my theory!