In the final scenes of Forbidden Planet, the "monster from the id" melts through an almost indestructible door with a combination lock which the commander jumbled in order to prevent access by the id. It is never explained how it is capable to use heat when in the former appearances it is simply an extremely ugly blob with claws.
Is the thing not only a projection but also has something like an independent mind (Morbius calls it the "evil self") and is therefore able to use the machine to project a heat-ray against the door? Or does Morbius himself project heat against the door with his subconscious mind?