User blog comment:Dhahn24/Is Thor smart or not?/@comment-3277907-20111122031229/@comment-3277907-20111122175935

Again, Thor himself is not the doctor, Donald Blake is the doctor, originally Donald Blake was a created being, but when Thor transformed into him, he ceased being Thor.

REcently it was revealed that Donald Blake is a real person, and when they switch back and forth, they are kept in a void.