Its a difficult line to draw when one thinks about it. What amount of evidence is needed to keep yourself sure, when do you start to change to get in line with the latest effort. In Tesauro a case before the European Court of Justice, the Attourney Generale gave his opinion on what constituted the cutting edge of scientific knowledge for the purposes of a defense at law. One of the more interesting observations was that the cutting edge of scientific thought, of thought in any fields, was that the right view was usually championed by some lone wolf, who was considered to be on the outside of mainstream opinion. Gradually the evidence for a position would mount up, and eventually the mainstream would move to adopt the position that was previously considered fringe.
There seems to be that what amounts to evidence to change your mind are heard to quantify. There is clearly no security in following the main stream, the main stream is never certified to be correct, in fact the mainstream seems to change its position with enough alacrity to justify little faith in them.
The question then becomes, besides our own subjective experience, what else justifies a change of opinion. I guess that there must be some procedure, an amount of evidence that satisfies that our previous thoughts were incorrect, but I’m left without any answers as to what changes the mind, except an assurance that somehow it does, in a gradual or a sudden manner. Just how is hard to know.