People with what we call mental illness can indeed serve well, and people who have no discernible mental illness - and that may be true of Trump - may not be able to serve, may be quite unfit. So it isn't always the question of a psychiatric diagnosis. It's really a question of what psychological and other traits render one unfit or dangerous.

There's more and more recognition that a carbon economy is dangerous to us economically. And there is increasing recognition that renewable fuels have economic value as well as obvious value for our health and our well-being and our survival. In fact, as you know, the economic revolution in renewable fuels has been impressive. It really had not been anticipated.

I'm a Brooklyn boy. I was born in Brooklyn, New York, and raised there, and spent most of my childhood there.

But I spent just two calendar years at Cornell University, though it was covering more than three years of work, and then went to medical school and did become interested in psychiatry, and even helped form a kind of psychiatry club in medical school.

There's an all-enveloping destructiveness in Donald Trump's character and in his psychological tendencies. But I've focused on what professionally I call solipsistic reality. Solipsistic reality means that the only reality he's capable of embracing has to do with his own self and the perception by and protection of his own self. And for a president to be so bound in this isolated solipsistic reality could not be more dangerous for the country and for the world. He's not psychotic, but I think ultimately this solipsistic reality will be the source of his removal from the presidency.

While Donald Trump doesn't have any systematic ideology, he does have a narrative, and in that narrative, America was once a great country, it's been weakened by poor leadership, and only he can make it great again by taking over. And that's an image of himself as a strongman, a dictator. It isn't the clear ideology of being a fascist or some other clear-cut ideological figure. Rather, it's a narrative of himself as being unique and all-powerful. He believes it, though I'm sure he's got doubts about it.

Donald Trump both disbelieves and believes in falsehoods, so that when he did thrive on his longstanding - the claim that Obama was not born in the United States - he's crazy like a fox in manipulating it because it gave him his political entrée onto the national stage. In order to make your falsehoods powerful, you have to believe in them in some extent. And that's why we simplify things if we say that Trump either believes nothing in his falsehoods and is just manipulating us like a fox or he completely believes them.