I think "snake oil salesman" only applies if the target of the epithet is knowingly perpetrating a fraud. You could (accurately, in my opinion) describe the th

I think "snake oil salesman" only applies if the target of the epithet is knowingly perpetrating a fraud. You could (accurately, in my opinion) describe the things Kurzweil is selling as "snake oil" but I wouldn't describe him as a "snake oil salesman." A whole lot of medicine practiced throughout human history has been based on ignorance, but I wouldn't describe medieval doctors (or whichever era) as "snake oil salesmen" because they believed in what they were selling. This is a pretty important distinction, in my mind.