Is it good to be open-minded?

It seems like everybody thinks of themselves or wants others to think of them as being open-minded. But what does that mean? Roughly, it seems to mean that you're willing to consider views other than your own, or you grant a sort of prima facie validity to views you haven't yet accepted.

All of us hold a whole slew of beliefs. Some of the beliefs we hold for good reasons and others we hold because we absorbed it unconsciously from our environment, and we haven't even thought about it critically enough to know if we hold it for good reasons or not. Some beliefs we hold very strongly, and some we hold lightly. We are more sure about some things than we are about others.

David Hume once said that a wise man proportions his belief to the evidence. I think that's a good maxim. The better the evidence is for some belief, the more confidence you should have that it's true.

With these things being the case, it would seem like we should be more open-minded about some things than about others. If you're absolutely certain that something is true, it would be irrational to be open-minded about its negation.

So it doesn't make sense to say that you are anybody is "open-minded" in a peanut butter kind of way. People are relatively open-minded and closed-minded to various ideas to varying degrees.