“It's not the bad ideas that do you in, it’s the good ideas. And you may say, 'That can't be so. That's paradoxical. What he [Graham] meant was that if a thing is a bad idea, it’s hard to overdo. But where there is a good idea with a core of essential and important truth, you can’t ignore it. And then it's so easy to overdo it. So the good ideas are a wonderful way to suffer terribly if you overdo them”