Conventional wisdom is a good heuristic. We tend to focus on the cases where it was wrong (the Earth is flat, the Earth is the center of the universe) more so than when the CW is correct. It's great to question/reaffirm widely held beliefs but my attention is a precious resource.
Think about it: specialized communities spring up for times when the collective wisdom of humans is wrong, not when it's right.
I don't see rationality as meaning we become hyperrational urkels. Our emotional faculties are part of us, and we should strive to grow to use them wisely. There is nothing irrational in this.
Persuasion as such is a Dark Art. However, there is an Art to telling the truth well, of telling it clearly, so that it can be understood. This is the art which I will spend my life attempting to master. Were one sufficiently advanced in this art, it seems to me that you could simply explain to a couple of brownshirts why they ought not to be brownshirts any more. I do not expect to reach this level on this side of the singularity, but I see no reason that it could not be done.
Conventional wisdom is a good heuristic. We tend to focus on the cases where it was wrong (the Earth is flat, the Earth is the center of the universe) more so than when the CW is correct. It's great to question/reaffirm widely held beliefs but my attention is a precious resource.
Think about it: specialized communities spring up for times when the collective wisdom of humans is wrong, not when it's right.
It is conventional wisdom that the conventional wisdom in the Middle Ages was that the world was flat. Your conclusion is right for the wrong reason.
http://en.wikipedia.org/wiki/Myth_of_the_Flat_Earth