An idea is a personality, not a fact. When it manifests itself within a person, it has a strong proclivity to make of that person its avatar: to impel that person to act it out. Sometimes, that impulsion (possession is another word) can be so strong that the person will die, rather than allowing the idea to perish. This is, generally speaking, a bad decision, given that it is often the case that only the idea need die, and that the person with the idea can stop being its avatar, change his or her ways, and continue.
