Accidental or not, that this seemingly trivial detail of Dagger of the Mind can be read as symbolizing the neutral neutralizer is both stunning and surprising to me. As I see it, there are two main ways to read this, assuming it is deliberate. The first is that the neutralizer is a hidden meaning in the more familiar and expected sun-symbol. The second is much subtler, as a sort of summary of the fact that Dr. Adams perverted his own profession. However it was arrived at, this really gives extra depth to the episode. Bravo! I assume you mean to say "...of mental illness."