I never want to be engaged in mind-reading, but it seems to me that the people who are shouting about him being mentally ill the loudest are doing so in a way to justify stifling everything he says, as if saying "he's mentally ill" ends any conceivable discussion about any of his ideas.

I think my general question remains. "How could an average outside observer distinguish between another's mental illness and a guy who's just a real out of the box thinker who might be wrong about many ideas but might also add value to the world by perceiving reality in an atypical way?"